For a moment, Danny stood quite still, his eyes and mouth wide open with utter surprise.

Looking about him warily the stranger picked up his bicycle and flung it into the dark waters of the pool.

Then the detective instinct in him realised that there must be something very “fishy” about a person who threw a good bike into a pond! He also realised that if he was to find out anything about this fishy person there was not a moment to be lost, so he scrambled down off the rickety old wall that he had been scaling, when he got his glimpse of the man, and set off across the yard.

The man had caught sight of Danny, he felt sure, just after flinging the bicycle into the pond. This was why he had vanished so quickly. The pond was hidden from Danny’s view when he got down from the wall. Would this give the stranger a chance to escape?

A moment later Danny was hurrying down the steep bank towards the marshy ground where the pond lay.

When he reached the pool there was no sign of the man. He peered about in the old barns, the rickety sheds, and the broken pig-sty—the man was nowhere. He went up into the mill. He climbed up ladders to the topmost floor. He peered between the great millstones. He leant far out of the windows and looked up and down the road and across the fields. There was no sign of the stranger.

“He must be a jolly good scout to have hidden so quickly,” said Danny to himself. “I wasn’t more than two minutes getting to the pond, but he managed to bunk.”

The only thing to do was to track the man down. Yes, there were the footmarks and a bicycle track in the soft mud of the little path that led down from the road to the marshy ground by the pond. Danny examined them carefully; they were quite fresh. He compared them with the drawing he had made in his pocket-book half an hour before, and they tallied exactly. So this was the same man; there could be no mistake.

With his heart thumping hard, Danny followed up the tracks. They led to the pond in a roundabout way, showing that the man had taken cover behind a hedge, the old barn, and a broken wall. By the side of the pond the wheel tracks stopped. Danny could see the firm, deep marks where the man had stood while picking up the machine and throwing it into the water.