Doctor Who: 10 Stories You Must Rewatch After The Power Of The Doctor

Series 12's opener kept us guessing right until the last second, when we were introduction to an all-new incarnation of the Master. Before assuming the guise of Rasputin in The Power of the Doctor, Sacha Dhawan made an electrifying debut as the Doctor's arch-enemy in both parts of Spyfall.

The Master is crazier than ever in this story, and is hell-bent on causing chaos and destruction for the sole purpose of his own amusement. This outing sees him forming an alliance with creatures from another dimension known as the Kasaavin, in order to get the Doctor's attention. This is to let her know of Gallifrey's destruction, which he seemingly caused and is responsible for.

Spyfall also features Sir Lenny Henry in an excellent starring role as Daniel Barton, the head of a faceless technology company that collaborates with the Kasaavin in order to rewrite human DNA and use it as a storage device.

In one of his best performances to date, Sacha Dhawan is the real star of this adventure, creating a tense and manic atmosphere throughout this two-part epic.