"If he would only drop his arms!" Jimmie mused. "I'd like to hit him with a ballclub!"
Directly the fellow did drop his arms, and at the same moment stepped out of the shelter of the doorway. This was what Jimmie had been waiting for, and he lost no time in acting.
The rope cut the air and descended over the intruder's head and arms. The lad's hours of practice while playing cowboy now proved to be of great worth.
Jimmie gave a quick jerk as the rope landed and he ran to the back of the room. He heard the other fall, and knew by the weight that he was dragging him.
When he gained the wall he switched on the light and reached to a shelf for a weapon. When he faced his captive he held an automatic revolver in his hand.
By this time a torrent of expletives was coming through the helmet opening where the air-hose had entered. The prisoner rolled about on the floor, trying to get to his feet.
"Whoo-pee!" shouted the boy. "Look what one can catch out of the ocean!"
A roar of rage was the only answer.
"Take off that helmet!" commanded the boy.
A muffled challenge came from the interior.