You were travelling on a ship called Campania with ciel as an extra hand for the investigation, you where in your room going through your stuff when suddenly you heard a scream and you saw that the ship was full of zombies and Ciel, Sebastian, Grell and Ronald fighting against the zombies and Undertaker

Ciel: "Sebastian!" Ciel shouted at his butler cause he was loosing a fight with a zombie

Sebastian: "Yes, my Lord..." Sebastian replied and went to help Ciel