Batman: Arkham Knight: The Riddler's Gambit was a prose tie-in novel written by Alex Irvine and released for Mass Market Paperback on June 23, 2015. It covered Riddler's story in the aftermath of the events of the Arkham City Incident and how he rebuilt his hideout in Wonder City over the remnants of Ra's Al Ghul's machinations.
THE OFFICIAL PREQUEL TO THE MOST EAGERLY AWAITED GAME OF 2015 -- BATMAN: ARKHAM KNIGHT!
The Joker's death has left a void in the Gotham City underworld--a void the Riddler seeks to fill in the deadliest way possible. Creating a path of death and destruction, the criminal mastermind places Batman and Robin in an unwinnable scenario, with the clock ticking down the moments to disaster.