Nighty Night

• Julia Davis as Jill Tyrell
• Rebecca Front as Cathrine “Cathy” Cole
• Angus Deayton as Don Cole
• Kevin Eldon as Terry Tyrell (Series 1)
• Ruth Jones as Linda
• Mark Gatiss as Glenn Bulb
• Felicity Montagu as Sue Forks
• Michael Fenton Stevens as Gordon Forks (Season 1; Guest Season 2)

• Kitty Fitzgerald as Joy (Season 1)
• Ralph Brown as Jacques (Season 2)
• Miranda Hart as Beth (Season 2)
• Llewella Gideon as Floella Umbagabe (Season 2)
• Loui Batley as Natalie (Season 2)

In the first scene of the series, Jill sits in a doctor's office with her husband Terry having just been told the prognosis of a medical examination. Jill, teary-eyed, exclaims "I mean why, why me?” Her husband turns to her comfortingly, and says, "Jill, let's keep this in perspective. It's me that's got the cancer."

Immediately after her husband begins cancer treatment, Jill goes to a dating agency to find another man, seemingly content in the knowledge that her husband will shortly die.

Jill uses her status as widow (despite Terry being still alive) to gain sympathy from those who work in Beauty by Jill, her suburban beauty salon which turns most clients suicidal after their treatment, and from the quiet couple who live across the street from her. Don is a family doctor and his wife Cath has multiple sclerosis and often uses a wheelchair. Using the pretence of caring for Cath, Jill gradually moves in with them, flirting with their son David and trying to break up their marriage and sleep with Don, all the while playing the sympathy card with Cath.

Jill occasionally visits her husband in hospital, where he is responding well to cancer treatment, in order to put her own spin on the good news from the doctors to leave Terry with the impression that he is really dying. When Jill finds out Terry is recovering, she admits him to a hospice and tells all her friends that he has died, and stages a twisted funeral where she gets all the attention.

Jill dresses as Don's former mistress Sandra to try to grab his attention, and prepares a meal for him while Cath is out. Don does not know anything about this and is pleasantly surprised. Later, Jill bends down, pretends to be incapable of moving and asks for Don's help. As Don is pulling her up from the ground, Cath enters and gets the wrong impression, to Don's irritation.

Running out of excuses for the ever-curious Terry, Jill is forced to take him home. She imprisons him in a spare room and begins starving and brutalising him, but explains she is doing it only to aid his recovery. When she runs into a simpleton, Glen, whom she met previously through the Lasso the Moon Dating Agency (he had described his personality as "Scottish"), she discovers that the deaths of his parents have left him extremely wealthy. As she pretends to fall in love with him, she coyly asks "Is either of your two houses nearby?"

Cath and Don later put forward their plans to move to Hopperton, a Christian retreat with a high population of lesbians. When Jill hears of this she throws a farewell coffee morning for them, livening it up by performing a pole dance routine to Kylie Minogue, whilst the neighbours watch in horror. The Hopperton nuns are also present and are duly shocked by Jill's antics. Meanwhile, Don has become extremely drunk and Cath announces she has had enough and is going on her own; she departs, leaving Don dazed and confused. Jill leaves the party to check on Terry, only to find him preparing to escape house arrest. She ushers him back upstairs and straps him to his bed wearing an adult nappy. Across the road at the party, Linda sees Terry at the window and thinks it's his ghost urging her to confess to their affair. She rushes across to Jill and tries to fight her way up to his attic bedroom. Jill thinks she has been unmasked until Linda tells her the purpose of her visit is to reveal that she was the woman Terry had slept with.

After the party Jill drags a tired Don to her place and realising she must be rid of Terry once and for all, runs upstairs and smothers him with a cushion. Don finds the bathroom, vomits and opens the bedroom door to find Jill lying seductively on the bed. Don, just wanting to lie down and too tired to be bothered, falls into Jill's arms.

Three weeks pass, and Jill has escaped the crime scene to live with Glen at his mansion. Under the pretence of being a Christian she forbids intercourse until their marriage, only to go downstairs one morning to find Glen has invited Gordon (Michael Fenton Stevens), the local vicar and friend of Jill, to arrange a wedding. The vicar explains Jill's neighbours had wondered where she had vanished to, and even suspected she had committed suicide given the strange smell coming from her house. Jill realises she is about to be found out now Gordon has discovered her, so confesses to murdering her husband to Glen (although she suggests it was a mercy killing). She puts poison in dishes of Angel Delight and encourages Gordon to eat some. As he chokes on it she tells Glen that if he loves her he would agree to take the blame for Gordon's and Terry's deaths and persuades him to make a telephone confession to the police. This done, Jill suggests that they both commit suicide by eating the Angel Delight, and he gives in to her persuasion. When it is her turn to eat the Angel Delight, she declares, "I'm not really hungry". The poison takes effect and Glen drops to the floor.

With Glen having taken the blame for Gordon and Terry's deaths, Jill is free to pursue Don. With the bodies of Terry and Linda hidden in the house, the last scene of the series has her dialing Don's phone number and seductively declaring "Hi Don, it's Jill..."

Glen has survived Jill's attempt to kill him, but having confessed to killing Terry and Gordon (who has survived in a vegetative state and is now in an iron lung) he is incarcerated in a secure unit for the criminally insane. Realising that she must inherit his money to fund her pursuit of Don she agrees to marry him and then begins a campaign to kill him. There is a mention in episode 1 that Linda was left in a coma following the finale of series 1, Linda is now alive and well and living in a caravan with her boyfriend Denis.

Still infatuated with Don, Jill steals the caravan (with Linda inside) and pursues him to Bude, Cornwall, where he and Cath are trying fix their marriage at a New-Age retreat called The Trees, which employs holistic and esoteric methods, run by non-recovering sex addict Jacques (played by Ralph Brown).

Once she has extracted their new address from Gordon's wife Sue, Jill sets off with Linda after accidentally pulling the plug on Gordon's life support. En route to The Trees they accidentally run over Floella Umbagabe, a therapist planning to work at the retreat. They store her body in their caravan and Jill assumes Floella's identity to gain access to the centre.

Convincing them she is reformed, Jill discovers that Don is trying to recapture his youth via bleached hair, surfing, and a younger girlfriend, Natalie (Loui Batley) while Cath has developed an unrequited crush on their marriage therapist Jacques. In an attempt to get closer to Don, Jill encourages his girlfriend's vanity by plastic surgery to ensure a modelling career, whilst urging Cath to pursue her counsellor. When Cathy reveals she is pregnant with Don's baby and that he will be having a vasectomy, Jill realises her chances of securing him permanently are running out, so with Linda she tries to obtain a semen sample from Don prior to surgery. Ultimately unsuccessful, she tries to seduce Cath and Don's 12-year-old son Bruce, and when he does not respond she claims to his parents that he repeatedly raped her and to allay any doubts pretends she is pregnant by him.

Meanwhile, Glen has tunnelled his way out of his cell and has tracked Jill to Cornwall; Floella Umbagabe has recovered and arrived at The Trees, effectively exposing Jill as a fraud.

The last episode is set 11 months after the events of the previous episode, after Cath has given birth to her baby Abigail. Don can no longer resist his attraction to Gordon's widow, Sue (and her chest) and tells her that he wants to move to Spain with her to start a new life. Jill overhears and assumes Don is talking about her, but armed with a gun, Glen finds Jill and threatens to kill her. Convincing him that she wants him and that she's pregnant with his baby, Jill once again deceives Glen into submission.

After Jill steals Abigail and claims she has given birth, the arrival of Floella, Glen and Cath threatens to unravel her web of lies. She is chased to a cliff where Cath confronts her about her fake pregnancy and her repeated attempts to seduce Don. They begin to fight while Don and Sue have sex on the rocks below. Cath's wheelchair is hurled off the cliff, killing Sue just before Cath pushes Jill off the cliff. Her fall is broken by a trampoline, and then by Don. Up on the cliffs Cath is arrested and taken away by the police while Jill rides off in a speed boat with a vomit-stained and unresponsive Don, towing Glen behind them on an inflatable inner tube.