Sergeant Oliphant and P. C. Gripper came forward with a stretcher. They put it down some distance from the body, which they now raised. As they did so, a daisy head, crumpled and sodden, dropped from the coat.

“Pick it up, tenderly,” Alleyn said as he did so, “and treat it with care. We must find the other two if we can. This murderer said it with flowers.” He put it away in his case. Oliphant and Gripper laid the body on the stretcher and waited.

Alleyn found a second daisy on the bank below the point where Colonel Cartarette’s head had lain. “The third,” he said, “may have gone down-stream, but we’ll see.”

He now looked at Colonel Cartarette’s rod, squatting beside it where it rested on the bank, its point overhanging the stream. Alleyn lifted the cast, letting it dangle from his long fingers. “The fellow of the one that the Old ’Un broke for him,” he said.

He looked more closely at the cast and sniffed at it.

“He hooked a fish yesterday,” he said; “there’s a flake of flesh on the barb. Where, then, is this trout he caught? Too small? Did he chuck it back? Or what? Damn this ruined ground.” He separated the cast from the line and put it away in his case. He sniffed into the dead curved hands. “Yes,” he said, “he’s handled a fish. We’ll go over the hands, fingernails and clothes for any more traces. Keep that tuft of grass that’s in his hand. Where’s the rest of it?”

He turned back to the riverbank and gathered up every blade of grass that was scattered where the Colonel had cut it. He examined the Colonel’s pocket knife and found that, in addition to having traces of grass, it smelt of fish. Then he very cautiously lifted the Old ’Un and examined the patch of stones where the great fish had lain all night.

“Traces there, all right,” he said. “Are they all off this one fish, however? Look, there’s a sharp flinty bit of stone with a flap of fish skin on it. Now let’s see.”

He turned the great trout over and searched its clamminess for a sign of a missing piece of skin and could find none. “This looks more like business,” he muttered and took out his pocket lens. His subordinates coughed and shifted their feet. Fox watched him with calm approval.

“Well,” Alleyn said at last, “we’ll have to get an expert’s opinion and it may be crucial. But it’s pretty clear that he made a catch of his own, that it lay on this patch, that a bit of its skin was torn off on this stone, that the fish itself was subsequently removed and the Old ’Un put in its place. It doesn’t look as if it was chucked back in the stream, does it? In that case he would have taken it off his hook and thrown it back at once. He wouldn’t have laid it down on the bank. And why was a flap of its skin scraped off on the stone? And why was the Old ’Un laid over the trace of the other fish? And by whom? And when?”

Fox said, “As for when: before the rain at all events. The ground shows that.”

“That doesn’t help, since he was killed before the rain and found before the rain. But consider, Br’er Fox, he was killed with a tuft of cut grass in his hand. Isn’t it at least possible that he was cutting his grass to wrap up his own catch? He had refused to touch the Old ’Un and had left it lying on the bridge. The people who knew him best all agree he’d stick to his word. All right. Somebody kills him. Is it that ‘somebody’ who takes the Colonel’s fish and replaces it with the Old ’Un?”

“You’d think so, Mr. Alleyn, wouldn’t you?”

“And why did he do it?”

“Gawd knows!” said Oliphant in disgust. Sergeants Bailey and Thompson and P. C. Gripper made sympathetic noises. Dr. Curtis, squatting by the stretcher, grinned to himself.

“What was the actual position of the killer at the time of the blow or blows?” Alleyn continued. “As I read it, and you’ll correct me here, Curtis, Colonel Cartarette was squatting on his heels facing the stream with the cut grass in his hands. The heel marks and subsequent position suggest that when he was struck on the left temple he keeled over, away from the blow, and fell in the position in which Nurse Kettle found him. Now, he was either belted from behind by a lefthander or rammed by a sort of crouching charge from his left side or struck from the front by a swinging right-handed swipe… Yes, Oliphant?”

Sergeant Oliphant said, “Well, pardon me, sir, I was only going to remark, would it be, for example, something like the sort of blow a quarryman gives a wedge that is sticking out from a rock-face at the level of his knee?”

“Ah!” said P. C. Gripper appreciatively. “Or an underhand serve, like tennis.”

“That kind of thing,” Alleyn said, exchanging a look with Fox. “Now there wasn’t enough room between the Colonel and the brink for such a blow to be delivered; which is why I suggested his assailant would have had to be three feet out on the surface of the stream. Now, take a look up-stream towards the bridge, Br’er Fox. Go roundabout, because we’ll still keep the immediate vicinity unmucked up, and then come out here.”

Fox joined Alleyn on the lower bank of the little bay at the point where it jutted farthest out into the stream. They looked up the Chyne past the willow grove, which hid the near end of the bridge, to the far end, which was just visible about forty feet away with the old punt moored in the hole beneath it.

Alleyn said, “Charming, isn’t it? Like a lead-pencil vignette in a Victorian album. I wonder if Lady Lacklander ever sketches from this point. Have you read The Rape of Lucrèce, Br’er Fox?”

“I can’t say I have, unless it’s on the police list, which it sounds as if it might be. Or would it be Shakespeare?”

“The latter. There’s a bit about the eccentricities of river currents. The poem really refers to the Avon at Clopton Bridge, but it might have been written about the Chyne at this very point. Something about the stream that, coming through an arch, “yet in the eddy boundeth in his pride back to the strait that forced him on.” Look at that twig sailing towards us now. It’s got into just such a current, do you see, and instead of passing down the main stream is coming into this bay. Here it comes. Round it swirls in the eddy and back it goes towards the bridge. It’s a strong and quite considerable sort of counter-current. Stay where you are, Fox, for a moment, will you. Get down on your sinful old hunkers and bow your head over an imaginary fish. Imitate the action of the angler. Don’t look up and don’t move till I tell you.”

“Ah, what’s all this, I do wonder,” Mr. Fox speculated and squatted calmly at the water’s edge with his great hands between his feet.

Alleyn skirted round the crucial area and disappeared into the willow grove.

“What’s he up to?” Curtis asked of no one in particular and added a rude professional joke about Mr. Fox’s posture. Sergeant Oliphant and P. C. Gripper exchanged scandalized glances. Bailey and Thompson grinned. They all heard Alleyn walk briskly across Bottom Bridge, though only Fox, who faithfully kept his gaze on the ground, was in a position to see him. The others waited, expecting him for some reason of his own to appear on the opposite bank.

It was quite a shock to Dr. Curtis, Bailey, Thompson, Oliphant and Gripper when round the up-stream point of the willow-grove bay the old punt came sliding with Alleyn standing in it, a wilted daisy head in his hand.

The punt was carried transversely by the current away from the far bank and across the main stream into the little willow-grove harbour. It glided silently to rest, its square prow fitting neatly into the scar Alleyn had pointed out in the down-stream bank. At the same time its bottom grated on the gravel spit and it became motionless.

“I suppose,” Alleyn said, “you heard that, didn’t you?”

Fox looked up.

“I heard it,” he said. “But I saw and heard nothing until then.”

“Cartarette must have heard it too,” Alleyn said. “Which accounts, I fancy, for the daisies. Br’er Fox, do we think we know whodunit?”