A shrug. "I'm not sure. I think the Doctor said the other two ghost ships weren't actually ghosts. One was a mind illusion thing, and what I thought were ghosts, wasn't. And the the other time was gaseous beings -- well I guess that was more zombies? UM. Oh and the time with the fish ghosts..." She thinks. What did the Doctor say it was? He didn't. "That was definitely ghosts." She licks her finger and holds it up in the air as this is doing something. It isn't. "Yeah, I'm pretty sure they are. But I'm not a ghostbustin' expert. Whenever he's here, he'll probably say it isn't."