E. Nigma, Consulting Detective

When the Joker traps Batman, Wonder Woman and Green Arrow decide against their better judgement to allow Riddler, who is trying to go straight, to help them track him down. Riddler assists them because Joker has stolen his riddle motives, as he deciphers Joker's riddles that lead him, Wonder Woman, and Green Arrow to Solomon Grundy's cell, the Iceberg Lounge, and the Gotham Art Museum.