Here's a new Batman: Arkham Origins Blackgate trailer that shows gameplay and gives you an idea of the backstory.
"Developed by Armature Studio, Batman: Arkham Origins Blackgate brings the core Arkham pillars to a handheld format for the first time to Sony and Nintendo handheld systems. Featuring stealth gameplay, free-flow combat, and Batman's infamous gadgets, Batman: Arkham Origins Blackgate captures the genuine Arkham feel players have come to appreciate.
Batman: Arkham Origins Blackgate is scheduled to launch for the PlayStation Vita and Nintendo 3DS. Batman: Arkham Origins developed by WB Games Montréal will be available for the PS3™, Xbox 360®, the Wii U™ system, and Windows PC. Both games will release worldwide on Oct. 25, 2013.