The Floating Admiral. Агата Кристи

right. Now I suppose whoever murdered him brought the boat back with the body in it. Suppose they got back round about slack water. The chap, whoever he was, sees the Vicar’s boat moored to the post in the stream, and hits upon the idea of putting the body in it. He goes alongside, lifts the body in, and then what does he do next? How is he going to cast off the Vicar’s boat? Tell me that?”

      “I don’t exactly see the difficulty,” replied the Inspector. “It wasn’t made fast with a chain and padlock.”

      “You didn’t see what I was getting at just now,” said Ware, with a touch of impatience. “Why, when he got back, it was dead low water, and the river had fallen three or four feet since the boat had been made fast. Don’t you see? Unless he was a very tall man, he wouldn’t be able to reach the knot unless he swarmed up the post. There was only one thing for him to do, and that was to cut the painter. And there’s one thing about that you may not have noticed. That painter is a nearly new piece of inch-and-a-half manilla.”

      “I noticed that it looked fairly new. But I can’t see for the moment what that’s got to do with it.”

      “Ever tried to cut new manilla with an ordinary pocket knife? No, I suppose not. But you can take it from me that you’d find it a pretty tough job. And when you’d finished you’d have left a frayed edge. But this rope was cut clean through, like as though it had been cut with one stroke of a very sharp knife. Anyway, cut it was, and the boat left to drift.”