It was the placid Hadley who was momentarily jarred out of his calm then. `But look here!' he protested, `the police surgeon said he died at a quarter to….'

'Hold on!' bellowed Dr Fell. He struck the top of the desk such a sharp blow with his cane that the sheet of mauve notepaper fluttered, off. `That's what I was hoping and waiting for. And to think I never took this man's testimony of the murder before! I nearly passed it up; My friend, I am grateful. I am profoundly grateful… Now, you're absolutely positive of that time, are you?'

`Positive. As I told you, my encounter with the young lady had jarred my watch. I stepped back into the door of the Wakefield Tower to see whether it was in danger of slipping off, and I noted the time just before I walked down to Water Lane.'

`Get out your watches, gentlemen,' rumbled Dr Fell, `and let's compare notes. Eheu! So! it's a quarter past six.

That's what I have, anyhow. What about the rest of you?' `Quarter past six,' said General Mason. `Thirteen and a half minutes past,' said Rampole.

`And I?' concluded Arbor. `Fifteen and one half minutes past, to the second. I never am wrong. This watch was made by…'

`Never mind,' interposed Dr Fell. `We shan't row about half a minute. There is, however, one thing I should like to ask. You said you were on your way out at this time, Mr Arbor. But the murder wasn't discovered until half-past two. How is it you were caught here when the detention order was issued?'

`I left one of my gloves behind, on the railing round the Raleigh first-edition in the Bloody Tower. They're — ah — rather special gloves,' he explained, carelessly. `Carter of Fifth Avenue does them for me, and I have no other pair of exactly this sort.'

General Mason looked pained, and Arbor lifted the shiny grey hat from his lap and indicated the gloves.

`I was all the way to the Strand in my cab before I remembered, and I returned. It was about twenty minutes to three when I arrived, and then I couldn't, get out.'

`I hope that cabby isn't still waiting,' the General mused. `It would be unfortunate,' Mr Arbor, if such an unfortunate witness got his head bashed in. Hold on! Wait! I remember now. There s something I wanted to ask, you.'

`With pleasure.' Arbor frowned. `You are…?'

'I'm the man you wanted to see,' the General replied, with some asperity. `I'm the deputy governor of the Tower. And what's more, sir, I'm damned if I let you paw over that Raleigh book. General Sir Ian Hamilton presented that to us. What was I saying? Oh yes. About the Raleigh. You said you had never seen it. Is this your first visit to the Tower?'

'It is.'

`The reason I asked is that you have all the names down pat. You speak familiarly of "Water Lane", and the Green, and all the rest of it, when you didn't go any farther than the Bloody Tower.'

`Perfectly simple,' said, Arbor, with the air of a detective speaking to his dull-witted assistant. `I dislike, asking directions.' From his pocket he produced one of the green pamphlets. `This little guide, with a map, which I studied before entering the Tower at all, gave me a thorough working knowledge.'

Dr Fell pulled at his moustache.

`I've got just one more question, my friend, and then you are free to go. Are you acquainted with Mrs Lester Bitton, your host's sister-in-law?'

`Unfortunately, no. You see, as I told you, I have never before stopped at Bitton's house. Mr and Mrs Bitton were away when I first arrived. They returned last night. I am told, but I only came back from my week-end this morning, and both were out of the house.'

`You wouldn't recognize her, then, if you saw her?'

`I'm afraid not.'

'Before you go, though,' Hadley suggested, `isn't there something you want to tell us?'

Arbor had risen with almost a shake of relief. He was buttoning his coat slowly, so as not to `seem in a hurry; but he stopped. `Tell you? I don't understand.'

`Any hints, or instructions, Mr Arbor? A valuable manuscript virtually belonging to you has been stolen, you know. Aren't you interested in, recovering it? It would seem that you are very easily diverted from the loss of a ten-thousand pound possession, considering the trouble you took to acquire it. Aren't you making any inquiries at all?'

Arbor, Rampole sensed, had been dreading that question. But he did not immediately speak. He adjusted his hat to a nicety, drew on his gloves, and hooked his umbrella over his arm.

`Just so,' he agreed. `But you are forgetting something. I want no unpleasantness in this matter, gentlemen; I have already outlined my reasons. I prefer not to use the assistance of the police. But I assure you I have not been idle. I have made certain contacts and leads which are — excuse me — not open to you. Good day, gentlemen.'

After he had gone there was a long silence. An expression of malignancy was on General Mason's face. He moved his hands in the air after the fashion of a burlesque hypnotist.

`Hocus-pocus,' he muttered. 'Allagazam. I hope you haven't got any more witnesses, Hadley. That's enough. First hats, and then love-affairs, and now manuscripts; It hasn't helped any. It's only mixed us up worse… What did you make of our aesthete?'

`As a witness,' said Hadley, `he was either too difficult or too easy, at various times. He started off smoothly enough. Then he went, into a complete funk at the mention of the murder. Finally, I'd swear he was, telling the truth when he described what he knew of the happenings here.'

`Meaning?' prompted the General.

'He obviously didn't know it was Driscoll who had been murdered here. At least, he didn't know it was the young chap he'd met at Sir William's. And it nearly knocked him over when he heard. Why?

`Put it this way. Arbor's clever, and he's tricky. He dislikes unpleasantness, because it upsets his own self-conscious dignity; but he has no more courage than a rabbit. You could see that in everything he said. Agreed?'

`Without a struggle,' said the General.

`All right. Now, he tried to make a joke out of the suggestion that he himself might have stolen that manuscript. But when you know Arbor's character, and Sir William's, it isn't quite so fantastic as it sounds. He knew the old man would raise thirty-eight different kinds of hell if he demanded his manuscript. But if the thing were stolen, Sir William could whistle for it. He had no case. Arbor could point all this out to him (by telephone, if necessary) after he'd safely got the manuscript and left the house.'

`I doubt whether Arbor would actually pinch the manuscript himself,' said the General, shaking his head. `He wouldn't dare?

'Wait a minute. Now, he wasn't worried about that theft. He wasn't exerting himself, you see. Well, who might have stolen it for him?'

The General whistled. `You mean…'

`It can't be!' snapped the chief inspector. `It would be too much. But the possibility stares us right in the face. I mean this. Arbor said he talked Poe in that house until even the family began to wonder; broader and broader hints. He also said that with the dark and mysterious hints Sir William constantly let fall, everybody must have known about, the manuscript. Certainly a clever young fellow like Driscoll couldn't', have failed to know it. And. Driscoll was there to dinner when Arbor did much of his talking….'

`Oh, look here!' General Mason protested. `An infernal counter-jumper like Arbor might have done it, of course. But if you're suggesting young Driscoll… Out of the question.'

`I didn't say it was true,' Hadley said, patiently. `But consider, Driscoll was discontented. Driscoll was always short of money. So suppose he takes Arbor aside and says, "Look here, if you happened to find that manuscript under your pillow one morning, what would it be worth to you?",' Hadley raised his eyebrows. `Perhaps Arbor then explained, as he might, that he was really the owner. Perhaps that didn't matter to Driscoll. But, since Arbor would have had to pay some sort of price to the old man if he bought it outright well? It was a good chance for a stroke of business.'

`NO!' boomed a thunderous voice.

Hadley jumped. There had been in that voice not only protest, but a sort of agonized appeal. They all turned to see Dr Fell lumbering to his feet.

`I beg of, you,' he said, almost imploringly — `I beg; and plead with you, whatever else you think of, anything in this case, not to get that absurd idea. If you do, Hadley, I warn you, you'll never, see the truth. Say whatever else you like. Say that the thief was Arbor, if you like. Say that it was General Mason or Father Christmas or Mussolini. But don't, I entreat you ever for a moment believe it was Driscoll.'

The chief inspector was peevish'. `Well, why not?'

`Cast your minds back a couple of hours. Damn it, where's my pipe? Ah. Well, we were speaking of Driscoll. And Sir William said he wasn't a coward. But one thing he most definitely did fear.'

And that?'

`He feared his uncle,' said Dr Fell. After a pause, while he spilled a considerable amount of tobacco in filling his pipe, he went on wheezily: `Look, here. Driscoll was an improvident sort, with expensive tastes. He lived entirely off his uncle's bounty. He got precious little from what freelance newspaper work he did, and Bitton helped him get along even with that.

'But — Bitton wasn't an' indulgent uncle. Quite to the contrary. He was always quarrelling with his nephew on some point or other. And why? Because he was so fond of him.

He had no son of his own. He had risen from small beginnings, and he wanted to see the boy exhibit some of his own violent energy. And do you think Driscoll didn't know that? Ha!' said the doctor, snorting. `Of course he did. The old man might squeeze the purse strings tighter than a slip knot.' But: Driscoll knew he was the old man's favourite. And when it came to the last. I rather suspect Driscoll figured conspicuously in the old man's will Didn't he, General Mason?'

`I happen to know,' the General said, rather guardedly, `that he wasn't forgotten.'

`So, Hadley, are you really mad enough to think the; boy would have endangered all that? Why, that manuscript was literally Bitton's most cherished possession. You saw how he gloated. If Driscoll had stolen it, and he ever had the faintest suspicion Driscoll had stolen it, out the boy would have gone for ever. You know Bitton's temper and, above all, his stubbornness. And what had Driscoll to gain? At most a few pounds from Arbor. Why should Arbor, a good man of business, give money to a thief for his own property? He would simply smile in that mincing way of his. "A thousand guilders? Come, take fifty! Or I might tell your uncle where you got this manuscript." — No, Hadley. The last thing in the world Driscoll would have done would have been to dare steal it. The person he feared most, I tell you, was his uncle.'

Hadley nodded thoughtfully

'Yes. Yes,' he said, `that's true. But why are you so aggressive on the point?'

Dr Fell sighed. He was very much relieved.

`Because, if you understand that, you're half-way, along the right track. I..' Wearily he raised his eyes to the door at another of the inevitable knocks. He went on vigorously: `But I was going to say that I absolutely refuse to listen to another witness this afternoon. It's past six and the pubs are open.'

A very tired looking Sergeant Betts entered.

`I've just been talking to the other visitors, sir,' he said to Hadley. `And I'm afraid it's been a long job. They all wanted to talk, and I had to listen for fear of missing something. But not one of them knew anything whatever, so I let them go Was that correct sir?'

`Yes. But keep those names and addresses in case you need them.' Wearily Hadley passed a hand over his eyes. He hesitated, and then looked at his watch. `'H'm. Well, it's getting late, sergeant, and we'll run along. I'll take charge of these articles on the table.'

He took down his overcoat and donned it slowly.

`Well, gentlemen,' said General Mason, `that seems to be all for the moment. And I think we could all deal with a large brandy and soda. If you'll do me the honour to come up to my rooms…?'

Hadley hesitated; but he looked at his watch again, and shook his head.

`Thanks, General. It's good of you, but I'm afraid I can't. I have to get back to the Yard; I've the devil's own lot of routine business, you know, and I've taken far too much time as it is. I shouldn't be handling the affair at all.' He frowned. `Besides, I think it's best that none of us go up. Sir William will be waiting for you, General. You know him best and you had better tell him everything. About Arbor, you see.?

'Hum! I'm bound to admit I don't like the job,' the other said. `But I suppose you're right.'

`Tell him we shall probably pay him a visit in Berkeley Square to-night, and to be sure everybody is at home.' Oh — yes. And the newspapers. There will be reporters here soon, if they're not being held outside already. For the Lord's sake don't say anything yourself. Just say, "I have no statement to make at the present time," and refer them to Sergeant Hamper.'

He was already gathering up the objects which had been in Driscoll's pocket. Rampole handed him an old newspaper from the top of a bookcase; he wrapped the crossbow bolt inside it and stowed it away in the breast pocket of his overcoat.

`Right you are. But at least,' said the general, `let me give you a stirrup cup before you go.' He went to the door and spoke a few words. In a remarkably short time the impassive Parker appeared, bearing a tray with a bottle of whisky, a siphon, and four glasses.

`Well,' he continued, watching the-soda foam as Parker mixed the drinks, `this has been an afternoon. It it weren't for poor Bitton and the damnable closeness of this thing, I should even call it entertaining. But I'm bound to say I can't make head or tail of it.'

`You wouldn't call it entertaining,' Hadley asserted, moodily, `if you had my job. And yet — I don't know.' There was a wry smile under his clipped moustache. He accepted a glass and stared into it. `I've been thirty years in this game, General. And yet I can't help getting something like a quickened pulse when I see "Scotland Yard has been called in on the case." What's the magic in the damned name?' I don't know. I'm a part of it. Sometimes I am it. But I'm still as intrigued as a naive old dodderer like Dr Fell.'

`But I always thought you were dead against amateurs„' said the General. `Of course you can hardly call the doctor, an amateur, but… '

Hadley shook his head. `Sir Basil Thomson, one of the greatest men the Yard ever had, used to say that a detective had to be jack of all trades and a master of none. The only thing I regret about the doctor here is the deliberate way he patterns himself after the detectives in sensational fiction; of which, by the way, he's an omnivorous, reader. His silences. His mysterious "Aha's!" his….’

`Thank you,' rumbled Dr Fell, satirically. He had put on his cloak and his long shovel-hat. Stumping round near the door, he accepted a glass from Parker. `Hadley,' he continued, `that's an outworn maxim, and a baseless slur on a noble branch of literature. You say that the detective in fiction is mysterious and slyly secret. All right; but he only reflects real life. What about the genuine detective? He is the one who looks mysterious, says "Aha!" and assures everybody that there will be an arrest within twenty-four hours.. In other words, he has all the pose, whether he has the knowledge or not. But, like the fictional detective, very sensibly he doesn't tell what he thinks, for the excellent and commonplace reason that he may be wrong.'

`All right,' said Hadley, — resignedly. 'If you like. Well, good health, gentlemen..!' He drained his glass and put it down. `I' suppose, doctor, this is a preamble to some mysterious predictions of yours?'

`I hadn't thought of doing so,' he replied. `But as a matter of fact, I will give you three hints about what I think. I won't elaborate them' — his scowl became ferocious as he saw Hadley's grin `because I may be wrong. Ha!'

`I thought so. Well, number one?'

`Number one is this. There was some dispute about the time Driscoll died. The only period in which we seem absolutely to be able to fix it lies between one-thirty when he was seen by Parker lighting a cigarette at the rail in front of Traitors' Gate, and ten minutes to two, which is the time

Doctor Watson said he died. Mr Arbor, coming into Water Lane at twenty-five minutes, to two, was positive there was nobody near the rail.'

`I don't see any implication there,' General Mason said, after a pause; `unless it's the implication that Arbor was lying. What's your second hint?'

`The second hint,' Dr Fell answered, `concerns that crossbow bolt. It was, as you saw, filed sharp into a deadly weapon. Now you are assuming, quite naturally, that this filing was done by the murderer.' We have also noticed that the same hand had started to file off those words, Souvenir de Carcassonne, but had stopped with three letters neatly effaced, and gone no farther…. Why weren't those other letters effaced? When we found the body, we were of course bound to learn of the bolt Mrs Bitton purchased at Carcassonne, and, since the victim was Driscoll, it would be too monstrous to assume a mere coincidence. I repeat: why weren't those letters effaced?'

`Yes,' said Hadley. `I'd thought of that point, too. I hope you're sure of the answer. I'm not. And the third hint?'

By this time Dr Fell, and the black ribbon of his eyeglasses, quivered to his chuckle.

`And the third hint,' he said, `is very short. It is a simple query. Why did Sir William's hat fit him?'

With a capacious tilt of his head he swallowed off his drink, glanced blandly, about the group, pushed open the door, and shouldered out into the mist.