"Doctor Who" is now half a century old, and an upcoming special commemorating the Time Lord's 50th anniversary will feature an all-star cast, including some familiar old faces.

Series veterans David Tennant and Billie Piper are joining the current Doctor Matt Smith and his new companion Jenna-Louise Coleman o the episode.

Brit screen legend John Hurt ("Alien," "Harry Potter") will also co-star.

Produced by BBC Cymru Wales for BBC One, the 50th anniversary special will be written by Steven Moffat and directed by Nick Hurran. Filming will begin this week in the U.K.  

Tennant starred in three series and several specials, and this will be his first time as the Doctor since 2010.

Likewise, Piper -- who played companion Rose Tyler for two series -- was last seen on the episode "The End of Time" in 2010.

"Doctor Who" returns with with eight episodes starting tonight at 8:00pm ET/PT on BBC America. Tonight's episode will formally introduce Coleman as the Doctor’s newest companion, Clara Oswald.