After five decades of adventures in time and space, Doctor Who has a lot of history to celebrate, and the Day of the Doctor makes full use of that weird and complicated back-story to mark the 50th anniversary, while still looking to the future.
A movie-length love letter to all things Who, The Day of the Doctor appeared on TV screens all around the world simultaneously over the weekend, with special 3D cinema screenings that sold out weeks ago.
It featured the return of David Tennant - still the most popular Doctor by far, according to a recent Doctor Who Magazine poll - and a previously unknown Doctor played by John Hurt.
The story sees the three versions of the same Time Lord team up - after the requisite bickering - to overcome yet another invasion of Earth by slimy, sucker-covered monsters, saving the world with wit and cleverness.