Discussion WMG / Prettylittleliars

He wants revenge for the killing of Charles/ Ce Ce. After all he was old enough to remember Charles as a child, and his excuse that Mrs. Dilaurentis convinced him that his brother was an imaginary friend is incredibly flimsy. And he later dated Ce Ce, and may have feelings for her as a result. This last one may be irrelevant, but he's also the only person of Garret and Ian's club who didn't die, and those two were also heavily involved in the secret events of the story