Celebrating The New Year
In the 9th century, three opposing factions narrowly succeeded in defeating a seemingly unbeatable enemy and hack its body into three pieces so that it can be hidden away in the farthest corners of the Earth.
However, the holder of one of the pieces is killed by an arrow before he can bury the piece; which is subsequently discovered by Lin and Mitch, two archaeologists, in Sheffield on New Year's Day in 2019. Not realising what they have discovered the last piece is unintentionally revived. It then remotely summons the other two fragments of itself to become whole again.
Meanwhile in the TARDIS, whilst watching New Year's Day fireworks from different time periods, The Doctor, and her three travelling companions, Graham O'Brien, Ryan Sinclair and Yasmin Khan, are alerted to this alien presence on Earth. The TARDIS arrives at an underground archaeological site where they meet the two archaeologists. Lin reveals that just before they had arrived she saw a large squid-like creature on a nearby wall. The Doctor goes to investigate but only finds a blob of slime. Unbeknown to everyone, the creature has attached itself to Lin's back and has taken control of her mind and body.
Returning to Graham's home, the crew discover that Ryan's hitherto absent father, Aaron, has returned, and wishes to make amends with his son for not being there, especially since Grace’s death. Graham is sceptical but supports Ryan when he decides to go with Aaron to a local cafe so the two can talk.
Meanwhile, The Doctor and Yasmin try to follow the creature, which has made Lin steal a police car and uniform. After examining the slime, The Doctor discovers that they are dealing with a Dalek - and in particular a Dalek Reconnaissance Scout
|The Dalek Reconnaissance Scout
The Dalek, still controlling Lin, arrives at an archive base, killing its guard and using his fingerprints to access the archives. Recovering a Dalek ray gun from the archive, Lin is forced to travel to a remote warehouse and after killing the owner she is made to construct a makeshift Dalek casing out of scrap metal.
Eventually, The Doctor and her companions find Lin freed from the now-rebuilt Dalek's control. After killing a military patrol, the Dalek flies to the UK’s Government Communications Headquarters, massacring the staff. There it attempts to summon a Dalek fleet in order to conquer Earth.
On realising what the Dalek is up to The Doctor, Graham, Ryan, Yasmin, Aaron and the two archaeologists head for GCHQ. They arrive just in time to scupper the fleet-summoning signal, destroying the Dalek's casing in the process - making them think they have also killed the Dalek.
However, the mutant survives and possesses Aaron, threatening to kill him unless The Doctor takes it to Skaro to rally the Dalek fleet. The Doctor is forced to agree, but instead she tricks the Dalek mutant by taking it to a supernova instead. With the TARDIS doors open Aaron and the Dalek mutant are nearly sucked out of the TARDIS but Ryan manages to save Aaron at the last moment as the Dalek mutant is cast into space and is sucked into the supernova.
Back in Sheffield, Ryan offers Aaron the chance to travel in the TARDIS, but Aaron declines. The TARDIS crew bid farewell to Aaron and the archaeologists and depart.