Lydia (Scott) is living a perfect life. A very successful real-estate agent, she is also involved in charities, a marathon runner, learns Italian, plays the oboe and regularly visits her grandmother. However, all of this success is thanks to Soft Voice (Powley), a voice she has been hearing in her head since she was a child and which has governed every move and decision she's made, right down to her choice of boyfriend and what yogurt she eats during the day. Lydia's life is upended one day when Soft Voice suddenly goes completely silent. After she is unable to continue doing her work or do her hobbies, things change again when Soft Voice is replaced by a new voice, Dark Voice (Cooke), who instead starts getting Lydia to follow her every own impulse, consequences be damned, leading to some even more unexpected twists and turns of her life.
Soft Voice provides examples of:
- Bad Boss: Trevor, Lydia's boss at the real-estate agency. While he usually puts on a pretend-friendly face, his dickishness really shines in Episode 7 when he fires another employee for getting upset at hearing about the murder of a Jean (though she didn't know her personally) and in an early episode when he reveals that he made calls to other real-estate agencies and effectively had Lydia blacklisted from working for them.
- Cool Old Lady: When Lydia takes Granny Night-Night to Berlin, she turns out to be very comfortable around gay people, being friends with several online, and to have a long and colorful past on the local nightclub scene.
- Dead Guy Junior: After killing Jean and getting Soft Voice back, Lydia gets a dog and names it "Jeanie", though she doesn't remember doing it or why she named the dog that.
- Distinction Without a Difference: Lydia's new boyfriend Grahem with an E is a solicitor, as opposed to Graham, who is a barrister, and takes issue with her confusing the terms even though both are essentially lawyers.note
- Fun with Homophones: Lydia has a boyfriend who is a barrister, but she is said to be more drawn to a barista at a coffee shop she regularly goes to; because the podcast takes place in Britain and the words are pronounced in RP English, they sound very similar.
- Gainax Ending: The season ends with the revelation that Lydia has the same voice as the one that Detective Blowe has been hearing in her head her whole life, and they go off to find others who are connected to them this way.
- Granola Girl: Jean is a free-spirited sort who doesn't care about spelling and writes poems on paper with her own blood (it's less disturbing than it sounds).
- Helpful Hallucination: Despite being a voice in her head and her controlling behavior, Soft Voice is genuinely helpful in Lydia's work, having a great instinct for what the buyer wants to hear and wants Lydia to be like.
- Heteronormative Crusader:
- Lydia shows attraction to both men and women, but Soft Voice seems to have steered her away from the latter, as suggested by a flashback:Lydia: Do I fancy her?
Soft Voice: Yes, but you shouldn't.
- Downplayed, but Grahem with an E is shown to be homophobic, unlike Graham, who didn't show any such behavior.
- Lydia shows attraction to both men and women, but Soft Voice seems to have steered her away from the latter, as suggested by a flashback:
- Nice Guy / Nice Girl:
- Despite being quite dull, Graham still comes off as friendly enough and takes Lydia's breakup pretty hard, while still offering his services if she ever needs legal help.
- Lydia's uncle Rick, who is one of the most genuinely pleasant and civil members of Lydia's family that we see when she visits them for Granny Night-Night's memorial service.
- Jean, the woman with the same voice as Soft Voice with whom Lydia starts a relationship, is a very friendly and accepting person.
- Replacement Goldfish: After killing Jean and getting Soft Voice back in her head, Lydia gets a new boyfriend also named Grahem (with an E) to replace Graham.
- Show Within a Show: Juicy Killings, a true crime podcast that Lydia and Jean listen to together in bed as they fall asleep.
- Sleeping Their Way to the Top: After getting her real-estate job back, it's implied that Lydia did something like this with her boss to do so; Soft Voice's narration implies that she sent him a sexy video.
- Spell My Name with an S: Grahem, Lydia's replacement boyfriend, is always identified as "Grahem with an E" to distinguish him for the original Graham.
- Sympathetic Inspector Antagonist: Detective Blowe, who investigates the murder of Jean, despite suspecting Lydia, is really only doing her job and isn't wrong about Lydia having done it. Also, the ending of the season has the two of them drive off together.
- This Is a Drill: Lydia is manipulated by Dark Voice into thinking that Soft Voice is trapped inside Jeanie's head, resulting in her taking a power drill to Jeanie's head, killing her in an effort to set Soft Voice free.
- Two Aliases, One Character: It eventually becomes clear that Soft Voice and Dark Voice are both just variations of the same voice in Lydia's head that sounded differently.
- Wham Line: The end of the first episode, revealing that the narrator has been Dark Voice:Dark Voice: How good, how very, very good life had been with Soft Voice. But now, I've moved in. My name is Dark Voice.