The annual Doctor Who Christmas special will have some extra spice this year: Not only is the Doctor regenerating from Matt Smith into Peter Capaldi, but the episode will include many more monsters than usual.

The official trailer, which landed on the BBC's YouTube channels on Wednesday, shows the evil A-listers Daleks and Cybermen but also the see-me-now-forget-me-later Silence and the terrifying Weeping Angels. It's unclear what purpose each serves, but the word "siege" is used, so perhaps they're all cooperating in an assault on the Doctor.

Considering the results of the last multi-monster team-up (2010's "The Pandorica Opens"), it may be an ill-conceived decision to overwhelm the screen and story with a grab bag of villainy. However, Steven Moffat's outstanding handling of the 50th anniversary special in November has convinced us to wait and see.

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Image: Adrian Rogers, BBC/BBC Worldwide 2013