Doctor Who and Sherlock — two shows helmed by the prolific British TV writer Steven Moffat — are both returning to our screens over the holidays. Matt Smith's Doctor has one last outing in the TARDIS on Christmas Day, while Sherlock will return from the dead on New Years Day.

The only thing that could make fans more excited would be a crossover between the two characters — and that's just what YouTube user John Smith (a favorite pseudonym for the the Doctor) has done with his latest upload.

The effect-filled video shows Sherlock stepping out of his Baker Street apartment and into the TARDIS for a chat with the Doctor. It has garnered nearly 400,000 views in its first day online.

If you're wondering how Smith managed to make the crossover look so realistic, here's a behind-the-scenes video he just posted.

Homepage Image: YouTube, John Smith