Doctor Who: The Snowmen Prequel - Vastra Investigates

Here's "Vastra Investigates" -- the prequel to the Doctor Who: The Snowmen Christmas Special.

Watch the video here. Airing schedule in your area of the world:

BBC One - Christmas Day 5.15pm
BBC America - Christmas Day 9pm
Space (Canada) - Christmas Day 9pm
ABC (Australia) - Boxing Day 7.30pm
Prime (New Zealand) - Boxing Day 8.30pm
Fox (Germany) - Boxing Day (time TBA)