Doctor Who 13.2 "War of the Sontarans"

Ending up during the Crimean War where the Doctor (Jodie Whittaker)  Yaz (Mandip Gill) and Dan (John Bishop) meet Mary Seacole (Sara Powell) who has opened The British Hotel (said enough times) in this episode who catches the Doctor pilfering through a dead soldier's pockets.  At least Mary thinks she is.  As they arrive at the Hotel, Dan and Yaz disappear.  Dan ends up in Liverpool being chased by Sontarans who have taken it over and the entire world.  As they are also fighting the British in the Crimean War.  Russia isn't part of the map the Lt General has, it's now known as Sontara and this includes China too.  Though he and Mary do recall Russia from somewhere before.  Mary tells the Doctor about the wounded Sontaran she nursed though he healed himself.  He's disgruntled as death was a far more fitting honour for him.  The Doctor tricks him into going back to his leader so he can parley with the Doctor.  As these Sontarans don't know the Doctor has undergone regeneration.  Thus giving her time to follow him to their base, along with Mary.

A man wakes up on another world and is taken by a Triangular Lantern asking "can you repair?"  It's the Temple of Atropos on a planet known as Time and the Mouri are in need of repair.  But he doesn't know what to do.  As Dan is chased by Sontarans into an alley since he's evaded the curfew, they're conked on the neck by his parents using a wok.  They tell him the world is being taken over and his mother adds that Liverpool was taken over first.  They have ships at the docks.  Dan infiltrates the docks and a ship and films everything for the Doctor.  Also witnessing the Sontarans brutally executing 'spies.'

The Doctor leaves Mary in their concealed base to take notes and observe as she meets for parley.  Admitting to the Sontaran leader, Skaak (Jonathan Watson) that she is the Doctor.  Who (!) was also President of Gallifrey* once. She wants them to leave and not engage in the war, however the Lt General has other plans, as he orders her removal from the scene.  Thus engaging in a bloody battle he has no chance of winning.  Realizing he can't, he asks the Doctor for help.  She explains to them who the Sontarans are and what they need to do to make them retreat.  I.e exhaust their supplies of air and food as they need to rest for 7.5 minutes as they can't remain in earth's air for so long.  That's why they wear armour.  The Doctor also steals onto one of their ships with Mary and makes contact with Dan who tells her about Liverpool and the footage.

The Sontarans plan on using the Flux chaos to make Earth a Sontaran outpost with the use of a temporal time attack.  Or as Dan asks a 'tempora' attack.  Yaz meets Vinder (Jacob Anderson) who tells her about the temple and the repair.  However, Swarm and his cronies, Azure and the Passenger also arrive at the Temple with nefarious intent and use Yaz to repair the Temple.  As the Doctor gets the TARDIS back also which takes them to the Temple.  

With the Lt General actually destroying the ships by planting gunpowder outside of them and igniting them, the Doctor once again questioning why she helps humanity and that they were retreating.  However they would only return so whatever happened was inevitable and this wouldn't have stopped them killing.  Also she herself explained that's all they've been cloned for.  Mary, for one, being thankful that the Doctor does save humanity. 

Atropos was one of the three Moirai, who were goddesses of destiny and fate.  Atropos was the eldest of the Three Fates and she was the one who selected how mortals would die.  She was the one who would cut their threads.  (Atropos as seen in the Supernatural ep My Heart Will Go On.)   But generally she is familiar as I kept annoying everyone by mentioning who she is, ha. 

*The Doctor was President in The Invasion of Time arc with Tom Baker (1978) in the episode The Deadly Assassin.  The Presidency was also alluded to in episodes with Doctors 5,6 and 7.  The Invasion of Time arc also involved the Sontarans.  So very relevant here.