The Gotham Knights World Premiere Trailer offers a first look at the next game in Rocksteady's Arkham series. The clip starts with the apparent death of Batman and ends with a 2021 release window. The video introduces the Batman family of Robin, Batgirl, Nightwing, and Redhood who take up Batman's vigilante mantle in his absence. This is accompanied by an Official 4K Gameplay Walkthrough Trailer with a look at some cooperative action featuring Batgirl and Robin. Word is: "Get a glimpse of open-world Gotham City where #Batgirl and #Robin join forces to take on #MrFreeze in one of several Villain encounters found within the city. They’ll use a variety of abilities, weapons, and unique combat moves to neutralize their foes." Here's the description from the world premiere trailer:

Batman is dead. It is now up to the Batman Family - Batgirl, Nightwing, Red Hood and Robin - to protect Gotham City, bring hope to its citizens, discipline to its cops, and fear to its criminals. You must evolve into the new Dark Knight and save Gotham from chaos.

Your legacy begins now. Step into the Knight.