Another really strong story. This one sees the Doctor and Clara team up with Calamity Jane and Oscar WIlde to fight an alien threat who appears to have met a previous incarnation of the Doctor. It's set in the Wild West town of Deadwood, and has a spooky idea at its core regarding a dead man in Wild Bill seemingly killing people from behind the grave as 'the masked gunman'.

I love how this story ties to 'The Forgotten', which in itself was a great Tenth Doctor comic story, and it's always fun seeing historical figures with the Doctor.