He rowed slowly towards the middle of the pond.

"You're about there now," said Bill at last.

Antony stopped rowing and looked about him.

"Yes, that's pretty well right." He turned the boat's nose round until it was pointing to the pine-tree under which Bill had lain. "You see my tree and the other coat?"

"Yes," said Bill.

"Right. Now then, I'm going to row gently along this line until we're dead in between the two. Get it as exact as you can-for your own sake."

"Steady!" said Bill warningly. "Back a little.... a little more .... a little more forward again.... Right." Antony left the oars on the water and looked around. As far as he could tell, they were in an exact line with each pair of landmarks.

"Now then, Bill, in you go."

Bill pulled off his shirt and trousers, and stood up.

"You mustn't dive from the boat, old boy," said Antony hastily. "You'll shift its position. Slide in gently."

Bill slid in from the stern and swam slowly round to Antony.

"What's it like?" said Antony.

"Cold. Well, here's luck to it."

He gave a sudden kick, flashed for a moment in the water, and was gone. Antony steadied the boat, and took another look at his landmarks.

Bill came up behind him with a loud explosion. "It's pretty muddy," he protested.

"Weeds?"

"No, thank the Lord."

"Well, try again."

Bill gave another kick and disappeared. Again Antony coaxed the boat back into position, and again Bill popped up, this time in front of him.

"I feel that if I threw you a sardine," said Antony, with a smile, "you'd catch it in your mouth quite prettily."

"It's awfully easy to be funny from where you are. How much longer have I got to go on doing this?"

Antony looked at his watch.

"About three hours. We must get back before daylight. But be quicker if you can, because it's rather cold for me sitting here."

Bill flicked a handful of water at him and disappeared again. He was under for almost a minute this time, and there was a grin on his face when it was visible again.

"I've got it, but it's devilish hard to get up. I'm not sure that it isn't too heavy for me."

"That's all right," said Antony. He brought out a ball of thick string from his pocket. "Get this through the handle if you can, and then we can both pull."

"Good man." He paddled to the side, took one end of the string and paddled back again. "Now then."

Two minutes later the bag was safely in the boat. Bill clambered in after it, and Antony rowed back. "Well done, Watson," he said quietly, as they landed. He fetched their two coats, and then waited, the bag in his hand, while Bill dried and dressed himself. As soon as the latter was ready, he took his arm and led him into the copse. He put the bag down and felt in his pockets.

"I shall light a pipe before I open it," he said. "What about you?"

"Yes."

With great care they filled and lit their pipes. Bill's hand was a little unsteady. Antony noticed it and gave him a rea.s.suring smile.

"Ready?"

"Yes."

They sat down, and taking the bag between his knees, Antony pressed the catch and opened it.

"Clothes!" said Bill.

Antony pulled out the top garment and shook it out. It was a wet brown flannel coat.

"Do you recognize it?" he asked.

"Mark's brown flannel suit."

"The one he is advertised as having run away in?"

"Yes. It looks like it. Of course he had a dashed lot of clothes."

Antony put his hand in the breast-pocket and took out some letters. He considered them doubtfully for a moment.

"I suppose I'd better read them," he said. "I mean, just to see-" He looked inquiringly at Bill, who nodded. Antony turned on his torch and glanced at them. Bill waited anxiously.

"Yes. Mark.... Hallo!"

"What is it?"

"The letter that Cayley was telling the Inspector about. From Robert. 'Mark, your loving brother is coming to see you-' Yes, I suppose I had better keep this. Well, that's his coat. Let's have out the rest of it." He took the remaining clothes from the bag and spread them out.

"They're all here," said Bill. "Shirt, tie, socks, underclothes, shoes-yes, all of them."

"All that he was wearing yesterday?"

"Yes."

"What do you make of it?"

Bill shook his head, and asked another question.