Jerry Gilroy and Biff Hooper went with Tony, while Phil Cohen went with Chet and the Hardy boys. Frank unlocked the door of the boathouse and went inside, followed by the others. But the familiar shape of the _Sleuth_ could not be seen. The front of the boathouse was open. The motorboat had disappeared. "The boat's gone!" he exclaimed in consternation. The other boys stared, amazed at this unexpected development. "It's been stolen!" cried Frank. "No one has a key to the boathouse but Joe and me." "It was here at noon!" exclaimed Joe. "I was in here for a few minutes before I went to school." "Who could have taken it?" asked Chet. "Do you think it could have been Paul Blum?" suggested Joe. The same thought had been in Frank's mind. "That's who it was! He wanted to make a quick getaway, so he figured his best chance would be by boat." "And perhaps he found out where our boathouse was, just so he could get even because we turned him over to the police," Joe put in. "He can't be very far away," Phil Cohen pointed out. "Your father said he just escaped a little while ago." Frank ran along the landing out to the front of the boathouse. For a moment he scanned the bay. Then he gave a sudden shout. "I see the boat! There's the _Sleuth_! I'd know it anywhere!" The others ran to his side, and Frank pointed out a flashing white shape heading far up the bay. There were very few boats out that afternoon and there was no mistaking the _Sleuth_ as it sped eastward. "Get Tony to chase him!" exclaimed Joe. "Quick!" They ran hurriedly out of the boathouse and made their way down to the ramshackle building where Tony Prito kept his craft. The other boys looked up in surprise as the Hardys and their companions entered. Tony had been just on the point of starting. "Paul Blum has stolen our boat!" Frank told him. "He's making his getaway in it now!" "Paul Blum!" exclaimed Tony. "Yes. The escaped prisoner. There's the boat now," declared Joe, as he pointed out toward the bay. In a flash, Tony grasped the situation. He leaped into the motorboat. "Jump in! We'll chase him." The Hardy boys scrambled into the boat, but Chet and the others stayed behind. "Too many cooks spoil the broth," explained Chet. "You'll need all the speed you can get out of that boat to catch him. We'd only delay you." Chet was eager to join in the chase, but he realized that the fewer passengers Tony's boat carried, the better would be their chance of capturing the fugitive. The other boys quickly took their cue from his attitude and declared that they would remain behind also. "We'll telephone to Barmet village," suggested Chet. "Perhaps a boat can put out from there and head him off." His remarks were drowned in the roar of the engine, as Tony's motorboat began to back slowly out into deeper water. It left the boathouse, then Tony turned the wheel and the motorboat headed about for the open bay.