No joke – or is it? Tonight’s episode appears to introduce this show’s rebooted origin story of one of the most infamous villains in the Batman universe: the Joker. The character in question is played by Cameron Monaghan from Shameless. Whether or not he turns out to be the actual Joker, though, is a riddle. Maybe we should check with E. Nigma – because we already know he will, in time, morph into The Riddler.