After a two-year hiatus, and the death-but-not-really-death of Clara Oswald (Jenna Coleman), The Doctor (Peter Capaldi) is back! Doctor Who returns to BBC America this Saturday (9/8c) with 12 episodes featuring the return of many familiar faces, some terrifying original monsters and a new companion for Twelve. Find out everything you need to know about Season 10 below!

It's Capaldi and Moffat's final season. Although Capaldi was asked to stay on, the actor decided that Season 10 would be his last out of fear of "phoning it in." As he told the New York Times, Capaldi "began to wonder, how many different ways can I find to say, 'The time vortex is going to open up and destroy the entire universe as we know it, unless we blow up that model spaceship over there'?"

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And after seven years at the helm, Steven Moffat will also be leaving Doctor Who, with the 2017 Christmas special marking his final episode. Broadchurch creator and Who writer Chris Chibnall will then take over showrunner duties for Season 11. "It took a lot of gin and tonic to talk [Chibnall] into this, but I am beyond delighted that one of the true stars of British television drama will be taking the Time Lord even further into the future," Moffat said last January.

The show is introducing its first gay companion. Pearl Mackie's Bill Potts -- whom the actor has described as funny, geeky and vulnerable -- will also be the show's first gay companion. "It shouldn't be a big deal in the 21st Century," Mackie said. "It's about time, isn't it? That representation is important, especially on a mainstream show. I remember watching TV as a young mixed race girl not seeing many people who looked like me, so I think being able to visually recognize yourself on screen is important."

Unlike Clara, whose entire character was intricately involved in Whovian mythology (damn you, Trenzalore!), Bill is just a regular woman who brings no previous knowledge of the Doctor with her into the TARDIS. "Bill is someone who asks the questions that nobody has asked for 53 years," Moffat told Doctor Who Magazine. "[She has the] irreverence and cheek to ask all the questions you're not supposed to ask on Doctor Who."

The regeneration will be a little different this time around. Although the past few regenerations have been fairly similar, Capaldi revealed to the Times that his is going to be a bit more complicated. "There's this notion now that it's the same process he's gone through every time, and that's not true," the actor said. "It's only the last couple of regenerations that have been, as it were, fairly straightforward ones. I can't go into the details of a lot of it, because I know what happens, but I don't know how it happens."

Nardole will be sticking around. After making appearances in the past two Christmas specials, Matt Lucas' Nardole will have a recurring role this season. As to how he's still kicking around the TARDIS after having his head cut off and stock on a cyborg's body a while back? That will all be explained this season, along with the secret mission he's working with the Doctor on.

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The Master is returning. In addition to the return of Michelle Gomez as Missy, John Simm will also appear this season as The Master. The villainous Time Lord spent a few weeks filming for the new season, and through some timey-wimey loophole will actually get to interact with Gomez's Missy. "They are absolutely wonderful together," Moffat told Radio Times. "They are hilarious, it's absolutely gorgeous. You're in for a real treat. A real treat."

They're bringing back the Mondasian Cyberman. Capaldi's favorite Doctor Who villains, the original Mondasian Cybermen, will help close out Season 10, appearing in Episodes 11 and 12. This version of the Cybermen haven't been seen in decades, and when they resurface, they'll have some new companions: a photo from the set shows Mondasian, Cybus and Nightmare in Silver Cybermen together. While little is known about what brings the Mondasian Cybermen back, it has been revealed that Missy will also feature in the final two episodes of Season 10. Draw your conclusions as you will.

Poirot is in it! Obviously, the most exciting new addition to the Whoniverse is David Suchet, who will be appearing in Episode 4, "Knock," as The Landlord. Mr. Poirot himself tweeted his excitement about the gig, sharing that he "always wanted to be in an episode" of Doctor Who. This will also make a Poirot reunion of sorts, since Capaldi guest-starred in an episode in 1991.

As to what expect of "Knock," apparently the building The Landlord owns is infested by giant woodlice who, we predict, will probably pick off his tenants one by one and who will most definitely gross us all out.

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The Ice Warriors are getting an upgrade. Episode 9, written by Mark Gatiss, will feature the return of the Ice Warriors, who last appeared in 2013's "Cold War". But Gatiss revealed this will be "a different kind of Ice Warrior." Although he declined to explain what these changes will be, Gatiss did say the episode will be a "Jules Verne, Edgar Rice Burroughs story of derring-do."

The new villains are as creative as ever. There are tons of other exciting foes for the Doctor to face off against this season. Episode 2, "Smile," will feature murderous Emojibots who skeletonize anyone who isn't smiling. Episode 3, "Thin Ice," will take place in 1814 London where a serpent is living underneath the iced over Thames. Episode 5, "Oxygen," will feature the return of writer Jamie Mathieson ("The Girl Who Died," "Flatline," "Mummy on the Orient Express"). And while we don't know what the monsters in "Oxygen" will be, Moffat raved to Doctor Who Magazine about the episode, saying "it's like the best of 'old' Doctor Who meeting the best of 'new' Doctor Who." And finally, Episode 10, "The Eaters of Light," will feature a Scottish, well, Eater of Light.

There will be a three-parter. Instead of leaning heavily on two-parters again, Season 10 will be almost entirely standalone episodes with the exception of the trilogy made up of Episodes 6, 7 and 8 and the final two of the season. The three-parter will be unified by the introduction of a terrifying new enemy that Moffat calls "the Monks" (although that isn't their real name). Missy will also make her first appearance of the season in Episode 6, which was penned by Moffat.

The premiere will include a MAJOR spoiler. During a press screening of the Season 10 premiere, Moffat instructed spoiler-phobes to avert their eyes during the trailer for Episode 2. "At the very end of the trailer there is, frankly, an enormous spoiler -- a spoiler that may actually melt your brains," Moffat warned those in attendance.

To help those avoid the spoiler if they so choose, the trailer will feature a countdown block and an instruction to "blink now" to avoid the apparently salacious reveal. Of course, it will be up to you if you choose to listen.

Doctor Who returns Saturday at 9/8c on BBC America followed by the new spin-off Class.