There are now just a few weeks left to go before Westworld returns, and tomorrow HBO will release a full trailer for season 2 of the critically-acclaimed series. The TV remake of Michael Crichton's 1973 sci-fi thriller debuted in October 2016, and quickly won audiences over with its rich world full of mysteries and intriguing characters. We recently learned that, while season 1 was collectively referred to as 'The Maze' by showrunners Jonathan Nolan and Lisa Joy, season 2's title is 'The Door' - whatever that means.

Westworld boasts a stellar cast, including Evan Rachael Wood, Thandie Newton, Jeffrey Wright and James Marsden as some of the park's resident "hosts" - androids that are almost indistinguishable from humans, but who were created so that the wealthy could act out their most depraved fantasies upon them. Season 1 ended with the hosts rising up against the staff of Westworld, wreaking bloody havoc upon the world that was created for them. Season 2 will be about the hosts trying to build their own world from the ashes of the old - though Delos, Inc. probably won't relinquish Westworld without a fight.

Related: New Westworld Season 2 Footage Unveiled in HBO Promo

The official Westworld Twitter account released a 15-second teaser for the upcoming trailer, which will arrive at 11am E.T./8am P.T. on March 29. Among the brief clips shown are shots of Delos security operatives arriving by sea and attacking in vehicles, and a scene in which the Man in Black (Ed Harris) explains that the creators of Westworld "wanted a place hidden from God, a place they could sin in peace." Of course, Westworld wasn't the only such place that they built.

Westworld season 1 was built on a series of mysteries that fans delighted in unpacking: who was a host and who was human? What exactly is the maze? Who is the Man in Black? Some of the big questions were answered by the end of that season, while others were not, and there will surely be fresh mysteries and secrets to uncover in season 2. We will also see a new type of host - called a 'drone host' - which is somehow connected to "the corporation’s secret project which is hidden in plain sight in this park." Delos definitely has a secret agenda, and Bernard (Wright) will be trying to get to the bottom of it.

The second season of the show will also feature more flashbacks, as the young versions of Robert Ford (Anthony Hopkins) and William/The Man in Black (Jimmi Simpson) will be returning. Simpson has said that, although the big secret about the Man in Black's identity has been revealed, season 1 was only "scratching the surface" of the character. It seems that we've only just begun exploring this world.

More: New Westworld Season 2 Footage Unveiled in HBO Promo

Westworld season 2 premieres April 22, 2018 on HBO.