‘Doctor Who’: New trailer has Missy, Mars, and a Mondasian Cyberman

“This is the gateway to everything that ever was — or ever can be,” says Peter Capaldi’s Time Lord at the start of the just-released new trailer for Doctor Who season 10, Capaldi’s last.

Is he talking about the TARDIS? His own brain? One of K-9’s poops? Who knows! Regardless, the Doctor might as well be discussing the trailer itself, which is jam-packed with characters both new and — in the case of the Mondasian Cyberman — very old, at least when it comes to the real-life chronology of the show.

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Doctor Who co-stars Pearl Mackie and Matt Lucas. The new season premieres April 15 at 9 p.m. ET on BBC America and is followed by the series premiere of Doctor Who spinoff Class. The Doctor Who season premiere and the Class series premiere will also be screened in cinemas by Fathom Events on April 17 and 19. Tickets for those screenings are on sale now at the official Fathom Events website.

Watch that new trailer above.