The Black Arrow, by Robert Louis Stevenson. Part III.

In the unsettled years of England's War of the Roses, where a man stood on the issue of kingship could make his fortune... or end his life. Dick Shelton, a nobly-born lad, is on the cusp of manhood, and he is thrust bodily into this stew where allegiances shift under one's feet. Circumstances cause him to fall in with a gentlemaiden in boy's disguise. 

Until he learns of the deception, Dick is unaware that the young lady is an heiress whom his guardian Sir Daniel had kidnapped. And the introduction of an outlaw with a penchant for putting black arrows into the bodies of the men who had wronged him affords Dick a worrying hint - that Sir Daniel might have been the man that had murdered Dick's father!