Then all at once Dorrimore changed his methods.

He began fencing in earnest, and so rapid was the play of his sword that the eye could scarcely follow it.

Suddenly he muttered an oath as a red stain appeared on his arm.

Vane had been lucky enough to scratch him, probably more by accident than dexterity.
Dorrimore roused himself and his fencing became more vigorous.

Vane was being pressed very closely, and Dorrimore's thrusts were becoming more and more difficult to parry.