Our take
Peter Capaldi's goodbye is barely an adventure and more a snow globe of a story: two old men refusing to die, a soldier given a second chance, and the 1914 Christmas truce as its quiet centre. David Bradley's first Doctor is unsettlingly good, Mark Gatiss is touching as the Captain, and Capaldi's final soliloquy packs a punch. The plot is slight, but the feeling is huge, and the last minute hands over to Jodie Whittaker.
What happens
The South Pole, 1986. The Doctor is refusing to regenerate again when, out of the blizzard, the original Doctor appears, also trying to hold his own transformation at bay. They meet a confused British Army captain who has been taken from a bomb crater during the First World War. All three are lifted aboard a spaceship where a force called Testimony has been harvesting people's memories at the moment of death and recreating them as glass avatars. One of them is Bill Potts. With help from a Dalek the Doctor once knew, they learn that Testimony means no harm, and the two Doctors return the Captain to the front line during the Christmas truce of 1914. The Captain turns out to be a Lethbridge-Stewart. Both Doctors accept the inevitable, and the later one gives a last speech before he regenerates into a woman, who is flung into space as the ship explodes around her.
Can the kids watch it?
Rated PG by the BBFC for mild threat, innuendo and language; a gentle, reflective special fine for most children from about 8.