They chugged steadily up the broad Cedar, the other boat in tow behind them. Less than five miles below the village the sound of the amphibian's engines echoed over the valley and they turned to see the big ship winging swiftly toward them. "Here comes trouble," cried Ford. "We'd better hit for a bayou where we can find some shelter." Tim opened the throttle of the outboard wide and swung the nose of the boat sharply to the left. The amphibian was coming fast. It was going to be close. Little spurts of water rose near them. Sladek or someone else on the plane was shooting at them. "Duck!" shouted Ford as the plane roared over them. "That was close," said Tim, pointing to the bottom of the boat where water was spurting through a half dozen holes. "Get under the shelter of the trees. We'll exchange boats." Tim shut off the outboard and they drifted under the dense foliage of the river bank. They pulled the other boat alongside and jumped into it. Tim glanced in the gas tank. There was plenty of fuel to finish the run to Auburn. The amphibian was circling overhead, hunting for the prey which now was sheltered by the trees. "What'll we do, wait here or try to slip along the bank?" asked Tim. "Waiting here won't do much good. We'll nose along shore and see if we can't give them the slip." Tim snapped the rope on the outboard and they churned ahead again, keeping as close to the trees as possible and threading their way along a bayou which paralleled the river. For a few minutes they were in comparative safety. Then an open stretch of the river loomed ahead and the amphibian swept down on them. "Sladek's going to land on the river," said Ford. "We'll have to duck back into the shelter of the bayou." "We can switch boats," suggested Tim. "I'll stay in the one with the holes and you may be able to slip away in this one." Ford shook his head. "Well, hardly. This is my party and I won't let you face Sladek and his gang alone." The amphibian, now a mile up the river, was settling down to land. The big ship skimmed the surface of the water, there were sheets of spray, and it glided swiftly toward them. Above the thrumming of the amphibian's motors came a sharper sound and Tim looked skyward. Then he grabbed Ford's arm. "Here comes Ralph in the Jupiter. Now we'll see some action." Dropping fast, the cream and green biplane roared down like an avenging bird. Ralph levelled off about twenty feet above the river and sped toward the amphibian. Tim saw something sticking over the side of the biplane. It looked like a gun but the distance was too great and the speed too fast to make sure. The men aboard the amphibian were caught unawares. The big craft slowed down and seemed to hesitate as the pilot waited for orders from Sladek.