Deadline reports that Mad Men star Jon Hamm will voice Herb Overkill in Illumination Entertainment’s Despicable Me prequel, Minions. He joins the already-announced Sandra Bullock, who voices Overkill’s wife and aspiring super-villain Scarlet. According to Deadline, Minions is set in the 1960s – before the title henchmen met Gru – and focuses on the Minions’ search for a new master after accidentally destroying all their previous ones through ineptitude. At a villain convention, they meet Scarlet, whose innocent appearance hides her ambition to become the world’s first female super-villain. Minions is scheduled to be released December 19, 2014.