In that suspended moment when the gray mists began to whirl around them, Harold Shea realized that, although the pattern was perfectly clear, the details often didn’t work out right.

It was all very well to realize that, as Doc Chalmers once said, «The world we live in is composed of impressions received through the senses, and if the senses can be attuned to receive a different series of impressions, we should infallibly find ourselves living in another of the infinite number of possible worlds.» It was a scientific and personal triumph to have proved that, by the use of the sorites of symbolic logic, the gap to one of those possible worlds could be bridged.

The trouble was what happened after you got there. It amounted to living by one’s wits; for, once the jump across space-time had been made, and you were in the new environment, the conditions of the surroundings had to be accepted completely. It was no good trying to fire a revolver or scratch a match or light a flashlight in the world of Norse myth; these things did not form part of the surrounding mental pattern, and remained obstinately inert masses of useless material. On the other hand, magic.

The mist thickened and whirled. Shea felt the pull of Belphebe’s hand, clutching his desperately as though something were trying to pull her in the other direction.

Another jerk at Shea’s hand reminded him that they might not even wind up in the sameplace, given that their various mental backgrounds would spread the influence of the generalized spells across different space-time patterns. «Hold on!» he cried, and clutched Belphebe’s hand tighter still.

Shea felt earth under his feet and something hitting him on the head. He realized that he was standing in pouring rain, coming down vertically and with such intensity that he could not see more than a few yards in any direction. His first glance was toward Belphebe; she swung herself into his arms and they kissed damply.

«At least,» she said, disengaging herself a little, «you are with me, my most dear lord, and so there’s nought to fear.»

They looked around, water running off their noses and chins. Shea’s heavy woolen shirt was already so soaked that it stuck to his skin, and Belphebe’s neat hair was taking on a drowned-rat appearance.

She pointed and cried, «There’s one!»

Shea peered toward a lumpish dark mass that had a shape vaguely resembling Pete Brodsky.

«Shea?» came a call, and without waiting for a reply the lump started toward them. As it did so, the downpour lessened and the light brightened.

«Curse it, Shea!» said Brodsky, as he approached. «What kind of a box is this? If I couldn’t work my own racket better, I’d turn myself in for mopery. Where the hell are we?»

«Ohio, I hope,» said Shea. «And look, shamus, we’re better off than we were, ain’t we? I’m sorry about this rain, but I didn’t order it.»

«All I got to say is you better be right,» said Brodsky gloomily. «You can get it all for putting the snatch on an officer, and I ain’t sure I can square the rap even now. Where’s the other guy?»

Shea looked around. «Walter may be here, but it looks as though he didn’t come through to the same place. And if you ask me, the question is not where we are but when we are. It wouldn’t do us much good to be back in Ohio in 700 A. D., which is about the time we left. If this rain would only let up.»

With surprising abruptness the rain did, walking away in a wall of small but intense downpours. Spots and bars of sky appeared among the clouds wafted along by a brisk steady current of air that penetrated Shea’s wet shirt chillingly, and the sun shot an occasional beam through the clouds to touch up the landscape.

It was a good landscape. Shea and his companions were standing in deep grass, on one of the higher spots of an extent of rolling ground. This stretch in turn appeared to be the top of a plateau, falling away to the right. Mossy boulders shouldered up through the grass, which here and there gave way to patches of purple-flowered heather, while daisies nodded in the steady breeze. Here and there was a single tree, but down in the valley beyond their plateau the low land was covered with what appeared at this distance to be birch and oak. In the distance, as they turned to contemplate the scene, rose the heads of farblue mountains.

The cloud-cover thinned rapidly and broke some more. The air had cleared enough so they could now see two other little storms sweeping across the middle distance, trailing their veils of rain. As the patches of sunlight whisked past, the landscape blazed with a singularly vivid green, quite unlike that of Ohio.

Brodsky was the first to speak. «If this is Ohio, I’m a peterman,» he said. «Listen, Shea, do I got to tell you again you ain’t got much time? If those yaps from the D.A.’s office get started on this, you might just as well hit yourself on the head and save them the trouble. He’s coming up for election this fall and needs a nice fat case. And there’s the F.B.I. Rover boys — they just love snatch cases, and you can’t put no fix in with them that will stick. So you better get me back before people start asking questions.»

Shea said, rather desperately, «Pete, I’m doing all I can. Honest. I haven’t the least idea where we are, or in what period. Until I do, I don’t dare try sending us anywhere else. We’ve already picked up a rather high charge of magical static coming here, and any spell I used without knowing what kind of magic they use around here is apt to make us simply disappear or end up in Hell — you know, real red hell with flames all around, like in a fundamentalist church.»

«Okay,» said Brodsky. «You got the office. Me, I don’t think you got more than a week to get us back at the outside.»

Belphebe pointed, «Marry, are those not sheep?»

Shea shaded his eyes. «Right you are, darling,» he said. The objects looked like a collection of lice on a piece of green baize, but he trusted his wife’s phenomenal eyesight.

«Sheep,» said Brodsky. One could almost hear the gears grind in his brain as he looked around. «Sheep.» A beatific expression spread over his face. «Shea, you must of done it! Three, two, and out we’re inIreland — and if it is, you can hit me on the head if I ever want to go back.»

Shea followed his eyes. «It does rather look like it,» he said. «But when.»

Something went past with a rush of displaced air. It struck a nearby boulder with a terrific crash and burst into fragments that whizzed about like pieces o fan artillery shall.

«Duck!» shouted Shea, throwing himself flat and dragging Belphebe down with him.

Brodsky went into a crouch, lips drawn tight over his teeth, looking around with quick, jerky motions for the source of the missile. Nothing more happened. After a minute, Shea and Belphebe got up and went over to examine a twenty-pound hunk of sandy conglomerate.

Shea said, «Somebody is chucking hundred pound boulders around. This may beIreland, but I hope it isn’t the time of Finn McCool or Strongbow.»

«Cripes,» said Brodsky, «and me without my heater. And you a shiv man with no shiv.»

It occurred to Shea that at whatever period they had hit this place, he was in a singularly weaponless state. He climbed on the boulder against which the missile had destroyed itself and looked in all directions. There was no sign of life except the distant, tiny sheep — not even a shepherd or a sheep-dog.

He slid down and sat on a ledge of the boulder and considered, the stone feeling hard against his wet back. «Sweetheart,» he said, addressing Belphebe, «it seems to me that whenever we are, the first thing we have to do is find people and get oriented. You’re the guide. Which direction’s the most likely?»

The girl shrugged. «My woodcraft is nought without trees,» she said, «but if you put it so, I’d seek a valley, for people ever live by watercourses.»

«Good idea,» said Shea. «Let’s.»

Whizz!

Another boulder flew through the air, but not in their direction. It struck the turf a hundred yards away, bounced clumsily, and rolled out of sight over the hill. Still — no one was visible.

Brodsky emitted a growl, but Belphebe laughed.

«We are encouraged to begone,» she said. «Come, my lord, let us do no less.»

At that moment another sound made itself audible. It was that of a team of horses and a vehicle whose wheels were in violent need of lubrication. With a drumming of hooves, a jingle of harness, and a squealing of wheels, a chariot rattled up the slope and into view. It was drawn by two huge horses, one gray and one black. The chariot itself was built more on the lines of a sulky than those of the open-backed Graeco-Roman chariot, with a seat big enough for two or three persons across the back, and the sides cut low in front to allow for entrance. The vehicle was ornamented with nail-heads and other trim in gold, and a pair of scythe-blades jutted from the hubs.

The driver was a tall, thin freckled man, with red hair trailing from under his golden fillet down over his shoulders. He wore a green kilt and over that a deerskin cloak with arm-holes at elbow length.

The chariot sped straight toward Shea and his companions, who dodged away from the scythes round the edge of the boulder. At the last minute the charioteer reined to a walk and shouted, «Be off with you if you would keep the heads on your shoulders!»

«Why?» asked Shea.

«Because himself has a rage on. It is tearing up trees and casting boulders he is, and a bad hour it will be for anyone who meets him the day.»

«Who is himself?» said Shea, almost at the same time as Brodsky said, «Who the hell are you?»

The charioteer pulled up with an expression of astonishment on his face. «I am Laeg mac Riangabra, and who would himself be but Ulster ’s hound, the glory of Ireland, Cuchulainn the mighty? He is after killing his only son and has worked himself into a rage. Ara! It is runing the countryside he is, and the sight of you Fomorians would make him the wilder.»

The charioteer cracked his whip, and the horses raced off over the hill, the flying clods dappling the sky. In the direction from which he had come, a good-sized sapling with dangling roots rose against the horizon and fell back.

«Come on!» said Shea, grabbing Belphebe’s hand and starting down the slope after the chariot.

«Hey!» said Brodsky, tagging after them. «Come on back and pal up with this ghee. He’s the number one hero of Ireland.»

Another rock bounced on the sward and from the distance a kind of howling was audible.

«I’ve heard of him,» said Shea, «and if you want to, we can drop in on him later, but I think that right now is a poor time for calls. He isn’t in apally mood.»

Belphebe said, «You name him hero, and yet you say he has slain his own son. How can this be?»

Brodsky said, «It was a bum rap. This Cuchulainn got his girlfriend Aoife pregnant way back when and then gave her the air, see? So she’s sore at him, see? So when the kid grows up, she sends him to Cuchulainn under a geas.»

«A moment,» said Belphebe. «What would this geas be?»

«A taboo,» said Shea.

Brodsky said, «It’s a hell of a lot more than that. You got one these geasa on you and you can’t do the thing it’s against even if it was to save you from the hot seat. So like I was saying this young ghee, his name is Conla, but he has this geas on him not to tell his name or that of his father to anyone. So when Aoife sends him to Cuchulainn, the big shot challenges the kid and then knocks him off. It ain’t good.»

«A tale to mourn, indeed,» said Belphebe. «How are you so wise in these matters, Master Pete? Are you of this race?»

«I only wisht I was,» said Brodsky fervently. «It would do me a lot of good on the force. But I ain’t, so I dope it this way, see? I’ll study this Irish stuff till I know more about it than anybody. And then I got innarested, see?»

They were well down the slope now, the grass dragging at their feet, approaching the impassive sheep.

Belphebe said, «I trust we shall come soon to where there are people. My bones protest I have not dined.»

«Listen,» said Brodsky, «This is Ireland, the best country in the world. If you want to feed your face, just knock off one of them sheep. It’s on the house. They run the pitch that way.»

«We have neither knife nor fire,» said Belphebe.

«I think we can make out on the fire deal with the metal we have on us and a piece of flint,» said Shea. «And if we have a sheep killed and a fire going, I’ll bet it won’t be long before somebody shows up with a knife to share our supper. Anyway, it’s worth a try.»

He walked over to a big tree and picked up a length of dead branch that lay near the base. By standing on it and heaving, he broke it somewhat raggedly in half, handing one end to Brodsky. The resulting cudgels did not look especially efficient, but they could be made to do.

«Now,» said Shea, «if we hide behind that boulder, Belphebe can circle around and drive the flock toward us.»

«Would you be stealing our sheep now, darlings?» said a deep male voice.

Shea look around. Out of nowhere, a group of men had appeared, standing on the slope above them. There were five of them, in kilts or trews, with mantles of deerskin or wolfhide fastened around their necks. One of them carried a brassbound club, one a clumsy-looking sword, and the other three, spears.

Before Shea could say anything, the one with the club said, «The heads of the men will look fine in the hall, now. But I will have the woman first.»

«Run!» cried Shea, and took his own advice. The five ran after them.

Belphebe, being unencumbered, soon took the lead. Shea clung to his club, hating to have nothing to hit back with if he were run down. A glance backward showed that Brodsky had either dropped his or thrown it at the pursuers without effect.

«Shea!» yelled the detective. «Go on — they got me!»

They had not, as a matter of fact, but it was clear they soon would. Shea paused, turned, snatched up a stone about the size of a baseball, and threw it past Brodsky’s head at the pursuers. The spearman-target ducked, and they came on, spreading out in a crescent to surround their prey.

«I — can’t — run no more,» panted Brodsky.

«Go on.»

«Like hell,» said Shea. «We can’t go back without you. Let’s both take the guy with the club.»

The stones arched through the air simultaneously. The clubman ducked, but not far enough; one missile caught his leather cap and sent him sprawling to the grass.

The others whooped and closed in with the evident intention of skewering and carving, when a terrific racket made everyone pause on tiptoe. Down the slope came the chariot that had passed Shea and his group before. The tall, red-haired charioteer was standing in the front, yelling something like «Ulluullu» while balancing in the back was a smaller, rather dark man.

The chariot bounded and slewed toward them. Before Shea could take in the whole action, one of the hub-head scythes caught a spearman, shearing off both legs neatly, just below the knee. The man fell, shrieking, and at the same instant the small man drew back his arm and threw a javelin right through the body of another.

«It is himself!» cried one of them, and the survivors turned to run.

The small dark fellow spoke to the charioteer, who pulled up his horses. Cuchulainn leaped down from the vehicle, took a sling from his belt and whirled it around his head. The stone struck one of the men in the back of the neck, and down he went. As the man fell, Cuchulainn wound up a second time. Shea thought this one would miss for sure, as the man was now a hundred yards away and going farther fast. But the missile hit him in the head, and he pitched on his face.

«Get out the head bag and fetch me the trophies, dear,» said Cuchulainn.