He had hoped to shake the man off, but the great arms still clasped him.

The situation could not last.

Oscar took advantage of the moonlight to choose a spot in which to terminate it.

He had his bearings now, and as they crossed an opening in the wood he suddenly loosened his grip on the horse and flung himself backward.
His assailant, no longer supported, rolled to the ground with Oscar on top of him, and the freed horse galloped away toward the stable.
A rough and tumble fight now followed.

Oscar's lithe, vigorous body writhed in the grasp of his antagonist, now free, now clasped by giant arms.