About three miles below Playford.”

“That’s right.” Greystoke nodded. “He bought it last year, and I understand he goes down there most week-ends. Occasionally, I believe, he entertains friends. Now I could have the place watched, of course, either by my own people or by fixing things up with the local police. The trouble is that I daren’t take the risk. If Craig is really using it as his private headquarters any hint that we are showing an interest in it would put him on his guard immediately. Whoever I selected myself might be known to him by sight, and in a Thames village a plain-clothes policeman lounging about the towpath would stick out like a lighted buoy. No, what I want is something quite different—some normal, harmless young holidaymaker who will fit naturally into the landscape. Get the idea?”

“I think so, sir.” Owen grinned. “It’s a funny coincidence, but I really had some notion of putting in a day or two on the river, and, oddly enough, in that very neighbourhood. I am staying with a pal who has a punt laid up at Playford, and he told me I could borrow it whenever I liked.”

“Looks as though Providence were taking a hand in the game. What I am most anxious to obtain is a list of Mr. Craig’s visitors. I should be glad to have an accurate description of everyone who sets foot on the island, but the gentleman I am chiefly interested in is our friend from Carlton House Terrace. If there is any further trouble brewing he is pretty sure to be somewhere in the offing.”

“What sort of a chap is he, sir?”

“A man of about forty. Tall, long-faced fellow with very thin lips. Generally sports an eyeglass. His name—for Heaven’s sake keep this to yourself—is Manstein, Count Conrad von Manstein. He is that unpleasant mixture, a cross between a Prussian Junker and a genuinely fanatical Nazi, about the worst abortion that nature has yet produced. Exactly what his position is at the Embassy I don’t know. Some people say that he is Hitler’s personal representative, but the only thing I am practically certain of is that he was the moving spirit in the Medlicot affair. I regard him as the most dangerous man we are up against—a cunning, cold-blooded brute, utterly ruthless and without the slightest trace of fear in his whole composition.”

“Sounds rather an ugly customer,” remarked Owen cheerfully. “Well, I ought to be able to recognise him from your description.” He paused. “I think the best thing I can do will be to drift down there Thursday or Friday and hang around doing a bit of fishing below the weir. Lots of people spend their week-ends that way, so it won’t attract any particular attention. I’ve just remembered something else, too. There’s a pub in the backwater opposite, and if I keep my ears open I may pick up a few useful hints. Sure to be a certain amount of gossip floating about—always is in those riverside joints.”

“Very sound programme.” Greystoke nodded approvingly. “You will have to be careful, though—damned careful. Remember that we are dealing with people who stick at nothing, and if it came to their notice that you were asking questions about Otter’s Holt it’s more than possible that they might turn exceedingly nasty.