Welcome back to Doctor Who, Billie Piper! The British sci-fi series just shocked fans when, in the Season 2 finale, Ncuti Gatwa ‘s Doctor regenerated — and the Sixteenth Doctor appears to be played by none other than Piper!

The season finale of Doctor Who, ‘The Reality War,’ was shocking for many reasons. However, the biggest surprise involved an appearance by actress Billie Piper, who played Ninth and Tenth Doctor companion Rose Tyler.

Piper, now 42, originally played companion Rose Tyler in 2005 alongside Christopher Eccleston’s Ninth Doctor. She went on to appear opposite David Tennant and was later revealed to be the mythical "Bad Wolf" - a mysterious, universe-shaping figure. Now, she’s taken the role full circle by stepping into the shoes of the Doctor herself.