With Rupert Thorne missing and his replacement, Eddie Nygma (The Riddler) now wreaking havoc on Gotham, brutal street violence and brazen robberies escalate and the GCPD is spread too thin to slow it down. To get intel on Thorne's whereabouts and background on his new capo, Nygma, the Batman goes undercover in Blackgate prison in the guise of Matches Malone!