The Intergalactic Trials

The Intergalactic Trials was a 6 part story that featured Peter Capaldi as The Twelfth Doctor and Raffey Cassidy as Jayney. It takes place six months after the events of Twelve Nights.

Background
The Intergalactic Trials was teased in a 30 second trailer that followed the finale of Twelve Nights on Christmas Day and was announced alongside a character trailer featuring The Doctor, Jayney and The Shadow Proclomation on New Year's Day, although no other casting was confirmed. It was announced the following month that while each episode would stand alone, they would all intertwine into an epic finale.

Rather than each episode be written by a different writer, a writer's room would be formed with each writer developing a story. Five writers were confirmed, lead by Steven Moffat, the other four are Mark Gatiss, Catherine Tregenna, Toby Whithouse and Neil Gaiman. Moffat lead the story for episodes 1 and 6, Gatiss fronted 2, Tregenna fronted 3, Whithouse fronted 4 and Gaiman fronted 5.

It was later confirmed that acclaimed film director Peter Jackson would take the helm of all 6 episodes. Steven Moffat invited Russell T Davies and Julie Gardner back to executive produce alongside him.

Principal photography began in March in and around South Wales. During this time, various casting news was announced and many big names had joined the cast including Sir Ian McKellen (Not reprising his vocal role from 'The Snowmen'), Sir Patrick Stewart, Julie Walters and Emma Thompson, all in important roles.

The first full length trailer featuring footage from the series premiered at San Diego Comic Con in July and was swiftly shared on the official Doctor Who twitter account. The trailer confirmed the return of Michelle Gomez as Missy for at least 1 episode. The trailer's premiere was followed by a panel featuring the cast and crew, this was made up of all five writers, Peter Jackson, Peter Capaldi, Michelle Gomez, Emma Thompson, Sir Ian McKellen, Sir Patrick Stewart and via video link from the UK, Raffey Cassidy. Additional newly announced cast member, Steve Coogan, appeared in the closing moments via a pre-recorded message.

In August, BBC One confirmed that all six episodes would air on Saturday nights in the 19:30 timeslot over the course of six weeks. The first and last episodes would each be 90 minutes in length, with the other four being an hour. The first episode premiered on the second Saturday of October in both the UK and on BBC America in the US.

Sequel Series
Following the finale, a cliffhanger was left and Neil Gaiman teased that he'd been asked back to the writer's room for another series to air sometime in the late Spring/early Summer.

The Doctor Who Christmas special was replaced by a one off animated adventure featuring Michelle Gomez entitled 'Missy: Queen of Christmas' and depicted her reign as the town of Christmas' leader in a Grinch-style format. Following this, the BBC officially confirmed that the cast and crew of The Intergalactic Trials would return for a second series of the same format, with the series to premiere in late July.