It is rather trite to remark that the greatest and sublimest characters always have concealed in them somewhere a speck of human jelly that wobbles furtively behind the imposing armour-plate, as if Nature's sense of proportion refused to tolerate such a thing as a perfect superman. Achilles had his heel. The hard-boiled hoodlum weeps openly to the strains of a syncopated Mammy song. The learned judge gravely inquires: "What is a gooseberry?" The Cabinet Minister prances pontificalty about the badminton court. The professor of theology knows the Saint Saga as well as the Epistle to the Ephesians. These things are familiar to every student of the popular newspapers.

But to Simon Templar they were more than mere curious facts, to be ranked with "Believe-it-or-not" strips or popular articles describing the architectural principles of the igloo. They were the very practical psychology of his profession.

"Every man on earth has at least one blind spot somewhere," Simon used to say, "and once you've found that spot you've got him. There's always some simple little thing that'll undermine his resistance, or some simple little trick that he's never heard of. A high-class card-sharper might never persuade him to play bridge for more than a penny a hundred, and yet a three-card man at a race track might take a fiver off him in five minutes. Develop that into a complete technique, and you can live in luxury without running any risks of getting brain fever."

One of Simon Templar's minor weaknesses was an insatiable curiosity. He met Patricia at Charing Cross underground station one afternoon with a small brown bottle.

"A man at the Irving Statue sold me this for a shilling," he said.

The broad reach of pavement around the Irving Statue, at the junction of Green Street and Charing Cross Road, is one of the greatest open-air theatres in London. Every day, at lunchtime, idle crowds gather there in circles around the performers on the day's bill, who carry on their work simultaneously like a three-ring circus. There is the Anti-Socialist tub-thumper, the numerologist, the strong man, the Indian selling outfits to enable you to do the three-card trick in your own home, the handcuff escape king, the patent medicine salesman, every kind of huckster and street showman takes up his pitch there on one day or another and holds his audience spellbound until the time comes for passing the hat. Simon rarely passed there without pausing to inspect the day's offerings, but this was the first occasion on which he had been a buyer.

His bottle appeared to contain a colourless fluid like water, with a slight sediment of brownish particles.

"What is it?" asked Patricia.

"Chromium plating for the home," he said. "The greatest invention of the century — according to the salesman. Claimed to be the same outfit sold by mail-order firms for three bob. He was demonstrating it on a brass shell-case and old brass doorknobs and what not, and it looked swell. Here, I'll show you."

He fished a penny out of his pocket, uncorked the bottle, and poured a drop of the liquid on to the coin. The tarnished copper cleared and silvered itself under her eyes, and when he rubbed it with his handkerchief it took a silvery polish like stainless steel.

"Boy, that's marvellous!" breathed Patricia dreamily. "You know that military sort of coat of mine, the one with the brass buttons? We were wanting to get them chromed —"

The Saint sighed.

"And that," he said, "is approximately what the cave woman thought of first when her battle-scarred Man dragged home a vanquished leopard. My darling, when will you realize that we are first and foremost a business organization?"

But at that moment he had no clear idea of the profitable purposes to which his purchase might be put. The Saint had an instinct and a collecting passion for facts and gadgets that "might come in useful," but at the times when he acquired them he could rarely have told you what use they were ever likely to be.

He corked the bottle and put it away in his pocket. The train they were waiting for was signalled, and the rumble of its approach could be felt underfoot. Down in the blackness of the tunnel its lights swept round a bend and drove towards the platform; and it was quite by chance that the Saint's wandering glance flickered over the shabbily-dressed elderly man who waited a yard away on his left, and fixed on him with a sudden razor-edged intentness that was more intuitive than logical. Or perhaps the elderly man's agitation was too transparent to be ordinary, his eyes too strained and haggard to be reassuring… Simon didn't know.

The leading draught of the train fanned on his face, and then the elderly man clenched his fists and jumped. A woman screamed.

"You blithering idiot!" snapped the Saint, and jumped also.

His feet touched down neatly inside the track. By some brilliant fluke the shabby man's blind leap had missed the live rail, and he was simply cowering where he had landed with one arm covering his eyes. The train was hardly more than a yard away when the Saint picked him up and heaved him back on to the platform, flinging himself off the line in the opposite direction as he did so. The train whisked so close to him that it brushed his sleeve, and squeaked to a standstill with hissing brakes.

The Saint slid back the nearest door on his side, swung himself up from the track, and stepped through the coach to the platform. A small crowd had gathered around the object of his somewhat sensational rescue, and Simon shouldered a path through them unceremoniously. He knew that one of the many sublimely intelligent laws of England ordains that any person who attempts to take his own life shall, if he survives, be prosecuted and at the discretion of the Law imprisoned, in order that he may be helped to see that life is, after all, a very jolly business and thoroughly worth living; and such a flagrant case as the one that Simon had just witnessed seemed to call for some distinctly prompt initiative.

"How d'you feel, chum?" asked the Saint, dropping on one knee beside the man.

"I saw him do it," babbled a fat woman smugly. "With me own eyes I saw it. Jumped in front of the train as deliberate as you please. I saw him."

"I'm afraid you're mistaken, madam," said the Saint quietly. "This gentleman is a friend of mine. He's subject to rather bad fits, and one of them must have taken him just as the train was coming in. He was standing rather close to the edge of the platform, and he simply fell over."

"A very plucky effort of yours, sir, getting him out of the way," opined a white-whiskered military type. "Very plucky, by Gad!"

Simon Templar, however, was not looking for bouquets. The shabby man was sitting motionlessly with his head in his hands: the desperation that had driven him into that spasmodic leap had left him, and he was trembling silently in a helpless reaction. Simon slipped an arm around him and lifted him to his feet; and as he did so the guard broke through the crowd.

"I shall 'ave to make a report of this business, sir," he said.

"Lord — I'm not going to be anybody's hero!" said the Saint. "My name's Abraham Lincoln, and this is my uncle, Mr. Christopher Columbus. You can take it or leave it."

"But if the gentleman's going to make any claim against the company I shall 'ave to make a report, sir," pleaded the guard plaintively.

"There'll be no complaints except for wasting time, Ebenezer," said the Saint. "Let's go."

He helped his unresisting salvage into a compartment, and the crowd broke up. The District Railway resumed its day's work; and Simon Templar lighted a cigarette and glanced whimsically at Patricia.

"What d'you think we've picked up this time, old dear?" he murmured.

The girl's hand touched his arm, and she smiled.

"When you went after him I was wondering what I'd lost," she said.

The Saint's quick smile answered her; and he returned to a scrutiny of his acquisition. The shabby man was recovering himself slowly, and Simon thought it best to leave him to himself for a while. By the time they had reached Mark Lane Station he seemed to have become comparatively normal, and Simon stood up and jerked a thumb.

"C'mon, uncle. This is as far as I go."

The shabby man shook his head weakly.

"Really, I don't —"

"Step out," said the Saint.

The man obeyed listlessly; and Simon took his arm and piloted him towards the exit. They turned into a convenient cafe and found a deserted corner.

"I took a bit of trouble to pull you out of a mess, uncle, and the story of your life is the least you can give me in return."

"Are you a reporter?" asked the other wearily.

"I have a conscience," said the Saint. "What's your name, and what do you do?"

"Inwood. I'm a chemist and — a sort of inventor." The shabby man gazed apathetically at the cup of coffee which had been set before him. "I ought to thank you for saving my life, I suppose, but —"

"Take it as a gift," said the Saint breezily. "I was only thinking of our rails. I've got a few shares in the company, and your method of suicide makes such a mess. Now tell me why you did it."

Inwood looked up.

"Are you going to offer me charity?"

"I never do that. My charity begins at home, and stays on with Mother like a good girl."

"I suppose you've got some sort of right to an answer," said Inwood tiredly. "I'm a failure, that's all."

"And aren't we all?" said the Saint. "What did you fail at, uncle?"

"Inventing. I gave up a good job ten years ago to try and make a fortune on my own, and I've been living from hand to mouth ever since. My wife had a small income of her own, and I lived on that. I did one or two small things, but I didn't make much out of them. I suppose I'm not such a genius as I thought I was, but I believed in myself then. A month or so ago, when we were right at the end of our tether, I did make a little discovery."

The shabby man took from his pocket a small brass tube like a girl's lipstick case, and tossed it across the table. Simon removed the cap, and saw something like a crayon — it was white outside, with a pink core.

"Write something — with your pen, I mean," said Inwood.

Simon took out his fountain-pen and scribbled a couple of words on the back of the menu. Inwood blew on it till it dried, and handed it back.

"Now rub it over with that crayon."

Simon did so, and the writing disappeared. It vanished quite smoothly and easily, at a couple of touches, without any hard rubbing, and the paper was left without a trace of discoloration or roughness.

"Just a useful thing for banks and offices," said Inwood.

"There's nothing else like it. An ink eraser tears up the paper. You can buy a chemical bleacher, and several firms use it, but that's liquid — two re-agents in separate bottles, and you have to put on drops of first one and then the other. That thing of mine is twice as simple and three times quicker."

Simon nodded.

"You're not likely to make a million out of it, but it ought to have quite a reasonable sale."

"I know that," said Inwood bitterly. "I didn't want a million. I'd have been glad to get a thousand. I've told you — I'm not such a genius as I thought I was. But a thousand pounds would have put us on our feet again — given me a chance to open a little shop or find a steady job or something. But I'm not going to get a penny out of it. It isn't my property — and I invented it!.. We've been living on capital as well as income. This would have put us straight. It had to be protected."

The old man's faded eyes blinked at the Saint pitifully. "I don't know anything about things like that. I saw a patent agent's advertisement in a cheap paper, and I took it to him. I gave him all my formulae — everything. That was a fortnight ago. He told me he'd have to make a search of the records before my patent could be taken out. I had a letter from him this morning, and he said that a similar specification had been filed three days ago."

The Saint said nothing; but his blue eyes were suddenly very clear and hard.

"You see what it was?" In his weakness the shabby inventor was almost sobbing. "He swindled me. He gave my specifications to a friend of his and let him file them in his own name. I couldn't believe it. I went to the Patent Office myself this morning: a fellow I found there helped me to find what I wanted. Every figure in the specification was mine. It was my specification. The coincidence couldn't possibly have been so exact, even if somebody else had been working on that same idea at the same time as I was. But I can't prove anything. I haven't a shilling to fight him with. D'you hear? He's ruined me —"

"Steady on, uncle," said the Saint gently. "Have you seen this bird again?"

"I'd just left his office when — when you saw me at Charing Cross," said Inwood shakily. "He threw me out. When he found he couldn't bluff me he didn't bother to deny anything. Told me to go on and prove it, and be careful I didn't give him a chance to sue me for libel. There weren't any witnesses. He could say anything he liked —"

"Will you tell me his name?"

"Parnock."

"Thanks." Simon made a note on the back of an envelope. "Now will you do something else for me?"

"What is it?"

"Promise not to do anything drastic before Tuesday. I'm going away for the week-end, but Parnock won't be able to do anything very villainous either. I may be able to do something for you — I have quite a way with me," said the Saint bashfully.

This was on a Friday — a date that Simon Templar had never been superstitious about. He was on his way to Burnham for a week-end's bumping about in a ten-ton yawl, and the fact that Mr. Inwood's misadventure had made him miss his train was a small fee for the introduction to Mr. Parnock. He caught a later train with plenty of time to spare; but before he left the elderly chemist he obtained an address and telephone number.

He had another surprise the next morning, for he was searching for a certain penny to convince his incredulous host and owner of the yawl about a statement he had made at the breakfast table, and he couldn't find it.

"You must have spent it," said Patricia.

"I know I haven't," said the Saint. "I paid our fares yesterday afternoon out of a pound note; and I bought a magazine for a bob — I didn't spend any pennies."

"What about those drinks at the pub last night?" said the host and owner, who was Monty Hayward.

"We had one round each, at two-and-a-tanner a time. I changed a ten-bob note for my whack."

Monty shrugged.

"I expect you put it in a slot machine to look at rude pictures," he said.

Simon found his bottle and silvered another penny for demonstration purposes. It was left on a shelf in the saloon, and Simon thought no more about it until the following morning. He was looking for a box of matches after breakfast when he came across it; and the sight of it made him scratch his head, for there was not a trace of silver on it.

"Is anyone being funny?" he demanded; and after he had explained himself there was a chorus of denial.

"Well, that's damned odd," said the Saint.

He plated a third penny on the spot, and put it away in his pocket with a piece of paper wrapped round it. He took it out at six o'clock that evening, and the plating had disappeared.

"Would you mind putting me ashore at Southend, Monty?" he said. "I've got some business I must do in London."

He saw Inwood that night; and after the chemist had sniffed at the bottle and tested its remarkable properties he told the Saint certain things which had been omitted from the syllabus of Simon Templar's variegated education. Simon paced the shabby inventor's shabby lodging for nearly an hour afterwards, and went back to his own in a spirit of definite optimism.

At eleven o'clock the next morning he presented himself at Mr. Parnock's office in the Strand. The inscription on the frosted-glass panel of the door informed him that Mr. Parnock's baptismal name was Augustus, and an inspection of Mr. Parnock himself showed that there had been at least one parent with a commendable prescience in the matter of names. Mr. Parnock was so august a personage that it was impossible to think of anyone abbreviating him to "Gus." He was a large and very smooth man, with a smooth convex face and smooth clothes and smooth hair and a smooth voice — except for the voice, he reminded Simon of a well-groomed seal.

"Well, Mr. — er —"

"Smith," said the Saint — he was wearing a brown tweed coat and creaseless grey flannel trousers, and he looked agitated. "Mr. Parnock — I saw your advertisement in the Inventor's Weekly —is it true that you help inventors?"

"I'm always ready to give any assistance I can, Mr. Smith," said Mr. Parnock smoothly. "Won't you sit down?"

The Saint sat down.

"It's like this, Mr. Parnock. I've invented a method of chromium plating in one process — you probably know that at present they have to nickel plate first. And my method's about fifty per cent cheaper than anything they've discovered up to the present. It's done by simple immersion, according to a specified formula." The Saint ruffled his hair nervously. "I know you'll think it's just another of these crazy schemes that you must be turning down every day, but — Look here, will this convince you?"

He produced a letter and handed it across the desk. It bore the heading of one of the largest motor-car manufacturers in the country, and it was signed with the name of the managing director. Mr. Parnock was not to know that among Simon Templar's most valued possessions were a portfolio containing samples of notepaper and envelopes from every important firm in the kingdom, surreptitiously acquired at considerable trouble and expense, and an autograph album in which could be found the signatures of nearly every Captain of Industry in Europe. The letter regretted that Mr. Smith did not consider five thousand pounds a suitable offer for the rights of his invention, and invited him to lunch with the writer on the following Friday in the hope of coming to an agreement.

"You seem to be a very fortunate young man," said Mr. Parnock enviously, returning the document. "I take it that the firm has already tested your discovery?"

"It doesn't need any tests," said the Saint. "I'll show it to you now."

He produced his little brown bottle, and borrowed Mr. Parnock's brass ashtray for the experiment. Before Mr. Parnock's eyes it was silvered all over in a few seconds.

"This bottle of stuff cost about a penny," said the Saint; and Mr. Parnock was amazed.

"I don't wonder you refused five thousand for it, Mr. Smith," he said, as smoothly as he could. "Now, if you had come to me in the first place and allowed me to act as your agent —"

"I want you to do even more than that."

Mr. Parnock's eyebrows moved smoothly upwards for about an eighth of an inch.

"Between ourselves," said the Saint bluntly, "I'm in the hell of a mess."

The faintest gleam of expression flitted across Mr. Parnock's smooth and fish-like eyes, and gave way to a gaze of expectant sympathy.

"Anything you wanted to tell me, Mr. Smith, would of course be treated confidentially."

"I've been gambling — living beyond my means — doing all sorts of silly things. You can see for yourself that I'm pretty young. I suppose I ought to have known better… I've stopped all that now, but — two months ago I tried to get out of the mess. I gave a dud cheque. I tried to stay in hiding — I was working on this invention, and I knew I'd be able to pay everyone when I'd got it finished. But they found me last Friday. They've been pretty decent, in a way. They gave me till Wednesday noon to find the money. Otherwise —"

The Saint's voice broke, and he averted his face despairingly.

Mr. Parnock gazed down at the silvered ashtray, then at the letter which was still spread open on his blotter, and rubbed his smooth chin thoughtfully. He cleared his throat.

"Come, come!" he said paternally. "It isn't as bad as all that. With an asset like this invention of yours, you should have nothing to worry about."

"I told them all about it. They were just polite. Wednesday noon or nothing, and hard cash — no promises. I suppose they're right. But it's all so wrong! It's unjust!"

Simon stood up and shook his fists frantically at the ceiling; and Mr. Parnock coughed.

"Perhaps I could help," he suggested.

The Saint shook his head.

"That's what I came to see you about. It was just a desperate idea. I haven't got any friends who'd listen to me — I owe them all too much money. But now I've told you all about it, it all sounds so feeble and unconvincing. I wonder you don't send for the police right away."

He shrugged, and picked up his hat. Mr. Parnock, a cumbersome man, moved rather hastily to take it away from him and pat him soothingly on the shoulder.

"My dear old chap, you mustn't say things like that. Now let's see what we can do for you. Sit down." He pressed the Saint back towards his chair. "Sit down, sit down. We can soon put this right. What's the value of this cheque?"

"A thousand pounds," said the Saint listlessly. "But it might as well be a million for all the chance I've got of finding the money."

"Fortunately that's an exaggeration," said Mr. Parnock cheerfully. "Now this invention of yours — have you patented it?"

Simon snorted harshly.

"What with? I haven't had a shilling to call my own for weeks. I had to offer it to those people just as it stood, and trust them to give me a square deal."

Mr. Parnock chuckled with great affability. He opened a drawer and took out his chequebook.

"A thousand pounds, Mr. Smith? And I expect you could do with a bit over for your expenses. Say twenty pounds… One thousand and twenty pounds." He inscribed the figures with a flourish. "I'll leave the cheque open so that you can go to the bank and cash it at once. That'll take a load off your mind, won't it?"

"But how do you know you'll ever see it back, Mr. Parnock?"

Mr. Parnock appeared to ponder the point, but the appearance was illusory.

"Well, suppose you left me a copy of your formula? That'd be good enough security for me. Of course, I expect you'll let me act as your agent, so I'm not really running any risk. But just as a formality…"

The Saint reached for a piece of paper.

"Do you know anything about chemistry?"

"Nothing at all," confessed Mr. Parnock. "But I have a friend who understands these things."

Simon wrote on the paper and passed it over. Mr. Parnock studied it wisely, as he would have studied a Greek text.

Cu + Hg + HNO 3 + St = CuHgNO 3 + H 2 O +NO 2

"Aha!" said Mr. Parnock intelligently. He folded the paper and stowed it away in his pocket-book, and stood up with his smooth fruity chuckle. "Well, Mr. Smith, you run along now and attend to your business, and come and have lunch with me on Thursday and let's see what we can do about your invention."

"I can't tell you how grateful I am to you, Mr. Parnock," said the Saint almost tearfully as he shook the patent agent's smooth fat hand; but for once he was speaking nothing but the truth.

He went down to see Inwood again later that afternoon. He had one thousand pounds with him, in crisp new Bank of England notes; and the shabby old chemist's gratitude was worth all the trouble. Inwood swallowed several times, and blinked at the money dazedly.

"I couldn't possibly take it," he said.

"Of course you could, uncle," said the Saint. "And you will. It's only a fair price for your invention. Just do one thing for me in return."

"I'd do anything you asked me to," said the inventor.

"Then never forget," said Simon deliberately, "that I was with you the whole of this morning — from half past ten till one o'clock. That might be rather important." Simon lighted a cigarette ajid stretched himself luxuriously in his chair. "And when you've got that thoroughly settled into your memory, let us try to imagine what Augustus Parnock is doing right now."

It was at that precise moment, as a matter of history, that Mr. Augustus Parnock and his friend who understood those things were staring at a brass ashtray on which no vestige of plating was visible.

"What's the joke, Gus?" demanded Mr. Parnock's friend at length.

"I tell you it isn't a joke!" yelped Mr. Parnock. "That ashtray was perfectly plated all over when I put it in my pocket at lunchtime. The fellow gave me his formula and everything. Look — here it is!"

The friend who understood those things, studied the scrap of paper, and dabbed a stained forefinger on the various items.

"Cu is copper," he said. "Hg is mercury and HNO 3, is nitric acid. What it means is that you dissolve a little mercury in some weak nitric acid; and when you put it on copper the nitric acid eats a little of the copper, and the mercury forms an amalgam. CuHgNO 3 is the amalgam — it'd have a silvery look which might make you think the thing had been plated. The other constituents resolve themselves in H 2 O, which is water, and NO 2, which is a gas. Of course, the nitric acid goes on eating, and after a time it destroys the amalgam and the thing looks like copper again. That's all there is to it."

"But what about the St?" asked Mr. Parnock querulously. His friend shrugged.

"I can't make that out at all — it isn't any chemical symbol," he said; but it dawned on Mr. Parnock later.