Then there came a splashing of water, as though a barrel of it had been precipitated to the ground.

Several minutes later the pursuers returned, very sheepish and very wet from the deluge presented them by the wily Brick, whose voice, high up in the air from some friendly housetop, could be heard defiantly jeering them.
This event apparently disconcerted the leader of the gang, and just as he turned to Joe and Fred and Charley, a long and peculiar whistle came to their ears from the street--the warning signal, evidently, of a scout posted to keep a lookout.

The next moment the scout himself came flying back to the main body, which was already beginning to retreat.
"Cops!" he panted.
Joe looked, and he saw two helmeted policemen approaching, with bright stars shining on their breasts.
"Let 's get out of this," he whispered to Fred and Charley.
The gang had already taken to flight, and they blocked the boys' retreat in one quarter, and in another they saw the policemen advancing.

So they took to their heels in the direction of Brick Simpson's slip, the policemen hot after them and yelling bravely for them to halt.
But young feet are nimble, and young feet when frightened become something more than nimble, and the boys were first over the fence and plunging wildly through a maze of back yards.

They soon found that the policemen were discreet.