Frank had a glimpse of a dark figure racing down the rocky slope toward them. He leaped to the engine.
"Here they are!" roared a voice.
More footsteps came running along the shore. The gangsters were converging toward the cove. Frank worked hastily over the engine. There was a splutter and a roar as the motor responded. The boat began to back slowly out of the cove.
"Keep down," he cautioned his brother.
Joe ducked, and not a moment too soon, for a fusillade of shots suddenly crashed out from the shore. Bullets whistled overhead. Wood splintered as one of them struck the side of the boat. Frank heard a heavy splashing in the water and judged that one of the gangsters was wading out in pursuit.
The boat moved slowly out to the entrance of the cove. In the darkness it was a ticklish performance. Frank doubted if he could make it. At any time it demanded careful steersmanship, and now there was no time for caution. The cove entrance was merely a faint gray blur against the darkness of the rocks on either side. He guided the Sleuth toward it.
Shots crashed and echoed from the shore. A dark form suddenly rose up beside the boat, with revolver upraised, but Joe launched himself on the man with surprising suddenness. His fist shot out and crashed into the gangster's face. With a muffled cry, the fellow stumbled back and lost his balance, going beneath the waves. He rose again in a moment, waist-deep in water, spluttering and choking, but by that time the Sleuth was several yards away and the water was too deep to permit the fellow to wade out any farther. His revolver was useless, and he began to make his way back to shore, growling to himself.
The motorboat reached the cove entrance. The rocks loomed high on either side.
Frank held his breath. At any moment he expected to hear the dread sound of the scraping rocks, but the Sleuth glided through the narrow channel without mishap, then shot out to the open sea. He spun the wheel about, brought the boat forward, and a moment later the engine was roaring its staccato defiance to the gangsters in the cove.
Frank looked back. He could see flashlights bobbing up and down on the beach.