The BBC has released a minisode prequel to Doctor Who " The Snowmen " called "Vastra Investigates". Enjoy.
http://www.youtube.com/watch?v=Rirju6is4Sw&feature=player_embedded
Doctor Who "The Snowmen" airs on Christmas Day on BBC One at 5.15pm.
Related stories:
• Doctor Who : New Versions Of Theme Tune And Title Sequence For “The Snowmen”
• Doctor Who “The Snowmen” BBC America Trailer
• Spurious Awards Of The Week