This year’s Doctor Who Christmas special is the most eagerly anticipated in years thanks to Peter Capaldi’s regeneration into Jodie Whittaker. And after we here at Metro.co.uk got a sneak preview of the episode at the Science Museum in London, we can assure you that it’s well worth the wait.

An audience at the IMAX at the Science Museum was given a screening of Twice Upon A Time last night, with one element craftily sliced off the end – Jodie Whittaker’s first appearance. Steven Moffat announced that due to the judgement of ‘our overlord Chris Chibnall’, even fans seeing the rest of the episode would have to tune in on Christmas Day for the first appearance of the female Doctor. So even if we wanted to spoil the Doctor’s regeneration for you, we couldn’t. But have no fear – we won’t spoil anything for you here. Not just because the BBC would eviscerate us if we did, but because it would be a darn shame.

Twice Upon A Time is the perfect swan song for both Peter Capaldi and Steven Moffat. While the plots in recent series of Doctor Who have been chequered, this very special special has all the hallmarks of a Doctor Who classic.

Humour, surprises, nostalgia, festive flair, and a hell of a lot of emotion. Seriously, we’d have the Kleenex handy alongside your Quality Street. There’s even some exceptional easter eggs thrown in which will have diehard Who fans squealing when they are revealed. What we can tell you about the plot is what has already been revealed – Capaldi’s Doctor comes face to face with his first incarnation, played by David Bradley, as both Doctors struggle to accept their regenerations. Also in the mix is a mysterious Captain, played by Mark Gatiss, who we meet as he is pointing a gun at an enemy soldier – played by Doctor Who writer Toby Whithouse – in the trenches; and Bill Potts, played by Pearl Mackie.

That’s as much as we can say without risking the aforementioned evisceration, but trust us – how these characters come together will not disappoint. Mark Gatiss, a lifelong Doctor Who superfan, is brilliant as the Captain, weaving himself into the storyline perfectly. Meanwhile, David Bradley – who previously played William Hartnell in An Adventure In Space And Time – is a delight.

With the episode using old footage of Hartnell to link to the present episode, we’re reminded of how far back Doctor Who went, which is lampooned in the various sexist comments spouted by the first Doctor – seemingly a nod to all of the angry folks protesting the Doctor now being a woman. However, this is Capaldi’s episode. As the Doctor’s final battle was wrapped up in The Doctor Falls, the Christmas special can simply focus on Capaldi’s acting. His comedy timing shines through brilliantly, with his back and forth with Bradley a standout moment. And when it comes time for him to regenerate, we can promise you there won’t be a dry eye in the house.

Jodie Whittaker and Chris Chibnall are bound to usher in a hugely exciting, revolutionary and amazing era of Doctor Who. But after watching Twice Upon A Time, you will definitely feel a twinge at the departure of Capaldi and Moffat. Twice Upon A Time, the Doctor Who Christmas special, airs on Christmas Day at 5.30pm on BBC One.