Old enough to kill

"Fleance is the 15-year-old son of Banquo, a thane in the King's army. When his father is murdered, Flea escapes into the forest, alone and wounded, but is soon found by his new friend Hamish, the drunken porter, who has fled Macbeth's castle. They form an uneasy alliance with Elspeth, the young, beautiful and devious Third Witch. A sword-and-sorcery play for teenagers, spun off from Shakespeare's Macbeth, and full of ghosts, apparitions, witches, magic, sword fighting, and youthful romance" -- Publisher's website.