For some reason Grant was less excited than his companions, a fact which escaped the attention of the boys at that time.
"All ready!" whispered Fred. Quickly turning the key he opened the door and together the four boys darted into the boat-house.
Although the moon was shining, the interior of the room was somewhat darker than it had been on the dock. The boys, however, were able to see clearly the man who was still standing near the Black Growler. Not even when they rushed upon him did he turn his face toward them.
In their eagerness to secure him all four did their utmost to leap upon him at the same time.
A most amazing result, however, followed their desperate attempt. Despite his efforts to save himself, Fred, who pluckily was in advance, was pushed over the edge of the slip and with a loud splash fell into the river. Before he could check himself John followed his example. A yell came from Fred when he arose to the surface because at that moment the intruder, whom they had discovered in the boat-house, also followed the example set by the boys.
Meanwhile George and Grant had broken into loud laughter. George was bowed and slapping his sides as he moved about the room. Grant was laughing almost as loudly as his companion, although he did not move from the place where he was standing.
"Give us a hand," called Fred. "I can't see the ladder."
"It's right in front of you," suggested George, advancing to the edge and looking down into the water which was only about four feet below him. "There it is. Follow the sound of my voice."
"I don't see what there is so funny about all this," sputtered Fred as he climbed to the floor.
"Funny!" exclaimed Grant. "It beats anything I ever experienced."