From the description:
"Rat is no ordinary thief. A feral, filthy and malnourished child; he haunts the streets of the medieval city Anistigh and survives on what he can steal. When he tries to steal a purse and bungles it, a mob wants to cut off his hand as punishment, so to save himself he slips into a convenient shadow to hide. Rat thinks it's just another warm and comfortable shadow cast by the sun, but a clan wizard sees him create the shadow with his magic, an instinctive act of which Rat is unaware. Rat's magic is subtle, but potentially quite powerful, so he is adopted into the greatest of the Lesser Clans, adopted into a family, and given the name Morgin.
Morgin quickly grows into manhood and the clan teaches him wizardry and sorcery and swordsmanship. But as a clansman he inherits the enemies of the clan, and his shadowmagic proves to be a potent weapon. And when he comes into possession of a powerful talismanic sword, he's thrust into the forefront of the clan rivalries. "