We're playing 2 player co-op, and died our first attempt. After returning together, my husband threw open the doors and ran into the room to claim our gravestones quickly. Meanwhile, I was just outside waiting, and Thomas charged me right in the doorway. I dodged past him into the room to avoid the attack, and the game slammed the door behind me as presumably intended...with Thomas now locked out of his own arena. We had to fight him jukily through the door, since we couldn't get out and he couldn't get in!