Spoiler alert: This article contains Doctor Who spoilers.
What we know so far:
The Doctor is back. Ten years after returning from the television graveyard and more than 50 years after its first episode, Doctor Who returns to Prime this Sunday, airing the same day as in Britain.
Peter Capaldi is back for another round as the Doctor,while Jenna Coleman continues her run as companion Clara.
Following a string of new and inventive monsters, plus original takes on classic foes such as the Daleks, the series ended with the Doctor's old enemy, the Master, returning and turning the planet's dead into Cybermen.
But after a season of questioning his own goodness and quarrelling with his companion, the Doctor is ready for some lighter fun, so here's what to expect from everyone's favourite Time Lord this year ...
1. Some familiar villains are returning this season, beginning with Michelle Gomez reprising her role as Missy, the latest incarnation of the Doctor's arch-nemesis, the Master. After much fuss was made of the character regenerating into a woman, Missy and Gomez have seemingly been welcomed by fans and she headlines the first episodes, despite seemingly being vapourised last season; the latest trailer showed her delivering the Doctor's will to Clara.
The Daleks are, of course, back as well, as are the shapeshifting Zygons, who last terrorised the Doctor during the 50th anniversary. New monsters include a fire-breathing cat-man, giant robots and zombies with eyes on their hands.
Clara (Jenna Coleman) and The Doctor (Peter Capaldi).
2. This season has the most inter-connected episodes a season since the show's revival.
Show-runner Steven Moffatt, however, has teased that they won't be traditional two-parters and some will be "just linked" - make of that what you will. Moffatt has also said the 11th episode will have a big cliffhanger no one will see coming.
3. Fans can expect much more stability on board the Tardis this season. After spending much of season eight debating whether or not to stay, Clara is now 100 per cent committed to her role as companion. With her boyfriend, Danny, killed off last season, Clara has nothing holding her back. Coleman and Moffatt say she "no longer fears her own mortality" and will be more reckless. They say to expect the show to continue to focus on their relationship.
Maisie Williams is set to guest star in the new season of Doctor Who.
4. The guest list is impressive this season. The most notable star is Maisie "Arya Stark" Williams, whose highly secretive role has been teased since the start of the year. Appearing in at least the first episode, The Girl Who Died, we don't know if Maisie is playing friend or foe, but one trailer implied she and the Doctor have a longstanding connection.
Other guests include Bafta winner Rebecca Front, at present starring as the mean nurse synth in Humans, and Clare Higgins, Ingrid Oliver and Jemma Redgrave all reprise their roles.
5. Spoilers: after a two-year absence, the Doctor reunites with his wife this Christmas when Alex Kingston reprises her role as River Song. The Christmas special marks the first appearance of her character since Capaldi took over from Matt Smith. Again, her role is shrouded in mystery, but it will be interesting to see where in River Song's timeline the episode takes place.
