The trailer includes sly – and not so subtle – references to the BBC show's 798 episodes and 11 Doctors. Framestore tells us how they used VFX to bring it to (immortal) life.

The BBC has released a trailer of the upcoming Doctor Who 50th anniversary special – which will be shown on November 23, as well as being shown in cinemas. Drawing on the long history of the show, the trailer is peppered with references that should delight harcore fans – though even they will likely need to watch it multiple times to pick up them all.

The trailer was directed by Matt Losasso, with Framestore's Oliver Bersey acting as VFX supervisor. It kicks off with the first Doctor – played by Wiliam Hartnell – appearing in the the show's first ever scene in Totter's Yard: created using original footage mixed with a double.

To do this, Matt took a still from the original black-and-white series then composited element from a double over the top in Photoshop. The end result was a hi-res colour still that Ollie could use as a reference for his Flame work

"First off I did the general compositing: the look, the colour, and the tracking," says Ollie. "Then I gave it some subtle 2D manipulations to make it look 3D as we go past him.”

Following this we slingshot through a wide array of Doctor Who characters, creatures and paraphenalia: some of which were shot, some of which were added in Flame by Ollie.

The camera moves were largely recreated in Flame. Ollie says that this was a very difficult task – but one that made everything incredibly smooth and also allowed them to throw in even more references from the show.

“We had to pretty much take it apart and rebuild it” says Ollie. “I tracked the cameras, stabilized them then recomposited all the bits into the stable camera move, but I worked hard to create that same 3D depth using isolated 2D elements. Using this method gave us the opportunity to load it with all the Doctor Who items.”

The trailer also features a matte painting of a huge landscape stuffed full of Doctor Who references, which was also created by Ollie.