“London, 2164: Come for the sightseeing, stay because the Daleks won’t let you leave.”
Short Synopsis
The TARDIS crew land in London only to discover it’s gone all post-apocalyptic chic. The Daleks are back, and this time they’ve swapped quarries for actual landmarks. Earth has been invaded, humanity enslaved, and Barbara somehow still manages to keep her hair tidy. It’s the first time the Doctor truly fights for Earth’s future, and not everyone makes it out alive.
Extended Storyline
The TARDIS materializes by the Thames, and at first it looks like the gang finally landed somewhere familiar. But within two steps they realize London’s looking a bit… well… knackered. Streets are abandoned, posters are peeling, and all the pigeons are gone (which, frankly, should’ve been the first warning sign something apocalyptic had happened).
The Doctor, Ian, Barbara, and Susan start poking about and quickly discover Earth has been invaded by Daleks. Because of course it has. The metal pepperpots are back, this time with new toys: flying saucers, robot minions, and the ability to glide across actual landmarks instead of just wobbling in gravel pits.
The Daleks have enslaved what’s left of humanity, turning many into Robo-Men — basically brainwashed servants who shuffle around in tin hats looking like someone mashed a factory worker with a radio antenna. Our heroes meet up with a band of plucky resistance fighters, including the dashing David Campbell, who immediately has eyes for Susan. (Teenagers, even in the apocalypse, apparently have time for romance.)
From here, it’s war movie territory: sabotage missions, underground tunnels, desperate battles, and lots of running through bombed-out London. Barbara gets to show off by running over Daleks with a truck (arguably her finest moment). Ian does his usual manly grappling with machinery, the Doctor does his scheming, and Susan practices her "scream and twist ankle" routine… except this time she gets an actual emotional arc.
Turns out the Daleks’ grand plan is to hollow out the Earth’s core and turn the planet into a mobile spaceship. Because when you’re a genocidal alien, subtlety is overrated. Luckily, the Doctor and the gang (plus the resistance) manage to scupper their plans with a mixture of explosions, rebellion, and sheer pluck.
But then comes the heartbreak: Susan falls in love with David, and the Doctor — realizing she deserves a life of her own — locks her out of the TARDIS and forces her to stay behind. It’s the first major companion departure in Who history, and the First Doctor delivers a genuinely moving goodbye speech. (Even if it was essentially: “Sorry Susan, you’re grounded forever, now go snog that bloke while I vanish into the time vortex.”)