But rather to his own surprise, French found himself considerably impressed by the two men’s personalities and the way they told their story. Both were heavy and slow-witted and, French judged, without any imagination at all, and both seemed reasonably honest. After he had questioned them he felt very much inclined to accept his Chief’s view and to believe the tale.

“You say you found the rings by the light of a hand lamp,” he went on presently. “Very good. Come along down with me to this boat of yours and we’ll have another look by daylight. Perhaps you missed a few.”

The men didn’t think so, but they were very willing to do anything which got them out of the police station. They led the two inspectors to the dirtiest wharf that French had ever seen, and there hailing a man in a wherry, the four were put aboard the Thames lighter Fickle Jane.

She was a long low craft more like a canal boat than a lighter. Nine-tenths of her was hold, but at one end there was a tiny fo’csle and at the other an equally diminutive engine-room. She was steered by a small wheel aft.

“Now,” French said to the “crew,” “go and stand just where you were when the rings came down.”

Fuller moved to the fo’csle and took up a position on the port side of the companion.

“And where did the rings strike?”

“Couldn’t just say to a foot, guv’nor,” the man answered, “but abaht that there bolt ’ead or maybe a bit forra’d.”

The point he indicated was starboard of the companion and mid-way between it and the side of the boat. French saw that objects falling at that point might scatter in any direction, and he began a careful search for further rings.

In less than a minute he found one. It had rolled down along the strip of deck at the side of the hold and jammed itself in a crack of the coaming timbers.