The episode begins with a paramedic arriving at a suburban house.
Earlier in the day, Angela is preparing for her elderly mother Maggie's birthday party. When Angela tries to move the cake, her husband Jim jumps out at her through a hole in the table. Their brother-in-law Pat, who will be at the party, continually embarrasses Jim with practical jokes; Jim is planning a trick of his own to get back at Pat. Maggie soon arrives with Pat and his wife, Angela's sister Carol. Pat annoys Jim with pranks while Carol, an alcoholic, begins drinking from a hidden stash in a sunscreen bottle. Maggie reads out the birthday card Pat wrote for her: "Forget about the past, you can't change it. Forget about the future, you can't predict it. Forget about the present, I didn't get you one!" Carol lights the candles on the fake birthday cake, but Angela blows them out before the flammable papier-mache cake can catch fire with Jim underneath.
Whilst the others are out of the room, Jim convinces Angela to take his place underneath the cake. Pat comes in and begins talking about Jim's secret porn habit, with Jim trying to divert the conversation because Angela is still there. A drunken Carol appears, and Pat goes to get her a glass of water. She begins flirting with Jim, who turns her down. When Pat returns, Carol argues with him and throws the water over him; he leaves, and she confronts Jim. It emerges that they have been having an affair for several years. Carol wants Jim to leave Angela for her, but he becomes angry, aware that Angela can hear them. Maggie enters with Jim and Angela's daughter Katie. Carol tries to dance with Katie and announces that she's going to be Katie's stepmother. Jim yells at Carol, but Pat intervenes, revealing he has always known about the affair. Maggie decides to cut the cake, and stabs a large kitchen knife into it. Jim panics, thinking Angela is underneath; but she walks into the room at this point. It turns out she had gone to buy a real cake and didn't hear any of the conversation.
Just as Katie is about to tell Angela about Jim and Carol, Maggie begins choking on a plastic spider Pat put in her drink. Pat reaches for his phone (which was charging) to call for an ambulance, but touches the plug with wet hands and gets an electric shock. Jim appeals to Katie, who shoves the new cake into his face. The doorbell rings, and a paramedic appears, asking for Maggie. Everyone's confused as to how he arrived before they had a chance to call the emergency services; but he starts doing a striptease to the Casualty theme. Pat confesses to hiring a stripper as a birthday present for Maggie.
Later, Carol and Pat have left, and Maggie is chatting to Jim. As Maggie again reads out the joke from Pat's card, Angela and Katie come downstairs with luggage, having decided to leave Jim. He silently watches them go.
This episode contains examples of:
- The Alcoholic: Carol (complete with a hidden stash inside a sun lotion bottle.)
- Awful Wedded Life: Carol and Pat.
- Chekhov's Gag: Pat's birthday card for Maggie.
- Deadly Prank: Subverted with several scenes that make it look like there will be a serious accident with the cake. Later, Maggie starts choking because Pat put a plastic spider in her drink; but survives.
- Disaster Dominoes:
- Failed a Spot Check: Maggie remains completely oblivious to her family falling apart around her.
- Foregone Conclusion: The episode begins with the paramedic arriving, inviting the audience to guess what led to him being there. Subverted when it turns out he's a stripper.
- Four-Temperament Ensemble:
- Pat is Sanguine
- Carol is Choleric
- Angela is Melancholic
- Jim is Phlegmatic
- Jumping Out of a Cake: A variant. Jim plans to jump out from under the fake cake through a hole in the table.
- Lighter and Softer: The only episode of the first two series in which no one dies.
- Living in a Furniture Store: Angela and Jim's house looks like this, implied to be due to Angela having OCD; she becomes very tense over minor details like noticing that the tassels on the rug aren't straight.
- Nouveau Riche: How Carol sees Angela and Jim, though they're not flashy with their money.
- Only Sane Man: Katie
- Porn Stash: Pat and Jim disguise theirs as videotapes of Countdown.
- Pride Before a Fall: Jim believes his brother-in-law Pat plays practical jokes on him because he can't match him intellectually. So he plans to counterprank Pat at his wife's mother's birthday party, even though he's already sleeping with Pat's wife, who's also his wife's sister. There's no way this can end well.
- That Came Out Wrong: Maggie mentions that Pat made gag ice cubes shaped like "willies" (penises.) Later, she begins choking on her drink, and Pat admits he did something to the ice, causing Angela to respond:Angela: If she's choking on one of your willies ...!
- Your Cheating Heart: Jim and Carol have been having an affair for several years.