Former SIC of the Decepticons, he was resurrected by the alien Alpha Quintesson, to gather Energon and resurrect Unicron, the world-eater. However, Alpha Q ran out of energon before the process could be completed, leaving Starscream incomplete—his memory blank, and his body unstable, constantly shifting from a physical to an ethereal form, able to teleport by "ghosting" from location to location. 
But sometimes, he can recall a little girl named Alexis, who called herself his friend.