"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.
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.