Matt Smith, David Tennant

We suggest you sit down for this.

That's how mind-blowing it is to see Matt Smith and David Tennant share the screen in the latest trailer for the Doctor Who 50th anniversary.

TV characters who were supposed to die

In addition to our first glimpse at seeing Ten and Eleven working together — fez included — the trailer also features the first footage of the last great Time War, Gallifrey and the ominous return of Bad Wolf.

Watch the trailer below.

The Doctor Who anniversary special airs Saturday, Nov. 23 on BBC America.