Ghosts? With 10? And River?! Yes please, the twist at the end is spectacular as well.

Easily the greatest of the Tenth Doctor and River Song Big Finish set. A brilliantly spooky and atmospheric story concerning the most haunted planet in the universe, and an eery fog that's consuming its tourists. Although the twist that the Doctor and River we are following are the ghosts is obvious, it doesn't detract from the story, and its eery tone makes it a Big Finish highlight.