The upcoming Doctor Who Xmas special "The Snowmen" just got extra-special, with an exciting new prequel. Titled "Vastra Investigates—A Christmas Prequel," it features our favorite Silurian lady, played by Neve McIntosh, and a Victorian mystery.

In the new prequel episode, Madame Vastra is accompanied by her very own loyal companions Jenny (Catrin Stewart) and Sontaran Commander Strax (Dan Starkey).

Our interstellar/interspecies dynamic trio is called upon to investigate a good old-fashioned Victorian murder mystery. But where is Sherlock Holmes the Doctor when you need him?

Have a look!

(via BBC Doctor Who)