The two fell to the floor together, and rolled over, fighting like wild
cats.

Ken's adversary was smaller than he, but he seemed amazingly strong and
active. He wriggled like an eel, all the time making frantic efforts to
get his right hand free, and use his knife again.

But Ken, aware of his danger, managed to get hold of the fellow's wrist
with his own left hand, and held it in a grip which the other, struggle as
he might, could not break. At the same time, Ken was doing all he knew to
get his knee on his enemy's chest.

It was the darkness that foiled him--this and the eel-like struggles of
his adversary. At last, in desperation, he let go with his right hand, and
drove his fist at the other's head. He missed his face, but hit him
somewhere, for he heard his skull rap on the floor, while the knife flew
out of his hand, and tinkled away across the cement floor.

Ken felt a thrill of triumph as he heaved himself up, and getting his
knees on his adversary's chest, seized him with both hands by the throat.

Before he could tighten his grip came a tremendous shock, and he was flung
off the other as if by a giant's hand. As he rolled across the floor,
followed a crash as though the very heavens were falling. The whole ship
seemed to lift beneath him, at the same time stopping short as though she
had hit a cliff.

[Illustration: 'Ken flung himself on the signaller.']