Things are desperate as Sainsbury’s, and only the Doctor and her trusty sonic screwdriver can save the day -- by freeing a stuck pound coin from a trolley and returning it to Ethel, an old age pensioner. What’s really depressing is that she’s proud of herself for doing so. After work, she goes out drinking at the Oddfellow’s with her workmates Cherrie and Cheese, just as she does every week. Once, after a night of heavy drinking, she admitted to her friends that she used to be a Doctor, and they’re the only ones who call her that now; everyone else knows her as “Susan Foreman”. Tonight, after several pints, the Doctor notices a satanic bearded man watching her from the bar, and fears that her past has caught up with her. She makes her move first, using Venusian aikido to paralyse every muscle in the man’s body. Unfortunately, it turns out that his name is Bob, and he wasn’t planning to take over the planet, but to chat the Doctor up. The Doctor has now become the centre of attention, and she responds by throwing up and passing out.
Cherrie takes the Doctor back to her flat and leaves her to sleep off her binge so she’ll be ready for work tomorrow. Before the Doctor can drop off, her past self appears in the mirror, and he’s disgusted with her behaviour. The Doctor escaped from the Time Lords by committing suicide in order to regenerate, and this caused him/her to change sex; however, rather than exploring the wonders of the galaxy and fighting evil monsters such as the Quarks, all she does now is spend her days working at Sainsbury’s and her nights drinking at the pub. The Doctor reminds her past self that the whole idea was to change her ways completely so that the Time Lords would never think to look for her here. Her past self isn’t convinced, but before he can muster a convincing argument, the new Doctor throws up again and passes out, hitting her head on the loo as she does so.
The next day, the Doctor shows up for work hung over and with a terrible bruise down the side of her face. Her supervisor, Baggit, calls her into his office to explain her behaviour -- and why he has not been able to confirm the references she used to get this job. Fortunately for the Doctor, her extremely unsatisfactory performance review is interrupted by a phone call; it seems that Princess Anne is in the area, and since one of her planned activities has fallen through, she is coming to officially open Sainsbury’s car park. The Doctor slips away as the delighted Baggit begins planning for the big event.
The Time Lords are in fact in the area, having deduced that the Doctor would try to hide out on his favourite planet. Fortunately for the Doctor, the elder Time Lord has personal issues with the time vector co-ordinator assigned to their case, and he and his younger colleague thus find that their clothing and money is thirty years out of date. Not only are they attracting hoots of derision for their ridiculous clothing, but they can’t afford rooms at the Savoy or, indeed, anywhere at all. Nevertheless, the elder Time Lord has staked his reputation on recapturing the Doctor and refuses to return to Gallifrey empty-handed, and he and his colleague thus set off to collect some money via the time-honoured Earth tradition of mugging an old lady (Ethel, as it happens).
Cherrie finds the Doctor balancing on a trolley in the car park and taking atmospheric readings from one of the strange rotor-blade mechanisms surrounding the area. She’s not sure why they disturb her so; all she knows is that ever since she started working at Sainsbury’s, she’s felt as though she’s been running in place. Nevertheless, she agrees to go out drinking as usual after work; these days, that’s the only thing that makes her mind stop working. At the pub that night, the Doctor asks Cheese about the rotor blades. Cheese explains that Sainsbury’s is built atop an old landfill site, and that the rotors are there to disperse noxious fumes from the rotting rubbish beneath the car park, thus preventing a build-up of toxic gases and an extremely disgusting explosion. As the Doctor listens to him, she misses a television news report about two oddly polite elderly muggers.
The Doctor’s pursuers use their ill-gotten gains to rent a bedsit in Crystal Palace and to buy some food -- although the younger Time Lord didn’t research the customs of Earth very well and has accidentally purchased dog food. As the younger Time Lord tries and fails to cook a dinner of baked beans, the elder Time Lord prepares to lure the Doctor out of hiding. He had originally intended to do something impressive at Jodrell Bank, but he’s had to downscale his plans, which now involve an etheric beam locator, the Crystal Palace television signal tower, and an unconvincing rubber alien mask.
After another night of drinking, the Doctor, Cherrie and Cheese stagger back to Cheese’s flat to go “batting on” -- i.e., drink all night until the dawn breaks and it’s time to start drinking again. While the Doctor experiences vodka for the first time, Cheese turns on the television -- and although Cherrie refused to let him put on any of his X-Files DVDs, a man in an unconvincing rubber alien mask appears on the screen, shrouded by interference and reciting galactic co-ordinates. Though very drunk, the Doctor realises that the co-ordinates are genuine, but she passes out before she can decide what to do about it.
Now that the elder Time Lord has faked evidence of an alien invasion, he believes that the news media will fly into a panic, the government will become involved, and the Doctor will be lured out into the open to offer his help. However, when the next morning dawns, there is no mention whatsoever of the transmission anywhere. It’s almost as if the humans have no idea that their planet is a target for alien conquest. The younger Time Lord, who has decided that Earth food is the worst food in the galaxy -- unsurprisingly, since he’s been eating lard -- comes up with an alternative plan which will get them away from this planet as quickly as possible.
The Doctor awakens with a severe hangover to find that she’s slept through an entire day; it’s now Monday, which is, fortunately, her day off. As the Doctor struggles to make sense of her muddled thoughts, her past self appears on the television, furious with her and insisting that she pull herself together. He claims that everything they’ve seen so far has been part of a diabolical alien plot, quite possibly by the Quarks, to kill Princess Anne by detonating the toxic gases from the landfill site. The Doctor takes a slug of vodka to pull herself together and rushes off to Sainsbury’s, drunk and hung over, babbling about an alien plot to blow up the car park and kill Princess Anne. Unsurprisingly, she is attacked and overpowered by Princess Anne’s bodyguards, and the mortally humiliated Baggit sacks her on the spot.
The mortally embarrassed Doctor slinks back home to drink herself into oblivion, but she finds her previous self reflected in a bottle of vodka. She is irritated with him, but must concede that he is just a reflection of herself, which means that she’s responsible for getting herself into this situation. She admits that she thinks she made a mistake; by lying low and failing to live up to her true potential, she may be hiding from the Time Lords, but she isn’t really being herself, either. The Doctor thus decides to return to her TARDIS, plug the Time Vector Generator back into place and get back to what she does best. Before going, she asks Cherrie and Cheese if they’ve ever considered trying to do something with their life other than just drinking every night, but they haven’t, so she simply bids them farewell.
When the Doctor first arrived on Earth, she abandoned her TARDIS outside a small village in the southwest of England, but she can’t recall exactly where. The first person she approaches for directions turns out to be a scarecrow; irritated with herself, she heads for the local pub to seek help, unaware that the scarecrow is watching her go. However, the Time Lords are waiting for her at the pub, disguised as an authentic rustic local bartender and an authentic rustic local poacher. When the Doctor arrives seeking help, the bartender directs her to the poacher, Old Joe, but claims that he’ll only help her if she buys him a pint of the local ale, Speckled Goat. The Doctor and Old Joe down several pints of Speckled Goat until Old Joe is satisfied that she really is the Doctor after all. He thus leads her to the field she’s looking for, but there, she finds the TARDIS surrounded by scarecrows -- which are in fact fully armed robots planted here by the Time Lords. After their first plan failed, they scanned the British Isles for anything in the shape of a police box, and after a few embarrassing mistakes they found the correct one here. Though Old Joe seems sympathetic to her plight, the Doctor vows never to surrender; however, she’s had too much Speckled Goat, and she drops the Time Vector Generator while brandishing it defiantly. She thus decides to just come in quietly.
Back on Gallifrey, the Doctor’s trial resumes, albeit somewhat informally, as the two Time Lords now seem more sympathetic to the Doctor after having themselves survived Earth. Sadly, they must inform the Doctor that her means of escape has embarrassed their superiors, as has the fact that she did so by changing gender, which is just icky. They’d originally intended to sentence the Doctor to exile on Earth, but now they have no choice but to sentence her to death instead. Somewhat peeved, the Doctor requests the opportunity to appeal by showing the Time Lords the evils she’s faced, but they’ve already seen the Quarks and weren’t impressed. The Doctor is thus sentenced to be confined to her TARDIS for the rest of her life; if she tries to escape, her ship will dematerialise forever, and it will be as if she never existed.
Sentence has been passed, but as there are no guards available to take the Doctor back to her TARDIS, she politely sees herself back. The Time Lords, as they had hoped, are rewarded with a promotion, and look forward to an easy life lounging around and occasionally signing pointless documents. The Doctor, meanwhile, enters the TARDIS to find a note from the younger Time Lord, “Old Joe”, claiming that he sympathises with her and is giving her the opportunity to escape with little fuss. The Doctor operates the TARDIS controls, but as it begins to dematerialise, it occurs to her a moment too late to wonder whether he was telling the truth...