Here we have the first trailer for the new DLC of Batman: Arkham Knight, including Batgirl and apparently Robin. The reason for Batman not to show up, is because the Joker (so it’s a prequel) will kill his hostage Gordon, if he sees the Bat. But it seems like other heroes are still welcome. The gameplay looks like the mechanics of the Arkham-games with a few new gadgets. If you should buy it or not depends on the length of the DLC, because the gameplay is already clear.