Early-twenties Londoner Sarah lives with her alcoholic mother and works in a local greasy café. There she meets Tom, a friendly, bouncy man, and they kick it off immediately.

Tom invites Sarah out that night and the pair take Ecstasy together. This, it seems, is a regular pastime for Tom but the first time for Sarah. Relishing the new high, Sarah is taken out to meet Tom's band of clubbing mates. She has never felt so free and thinks it is all down to Tom and this new drug. The couple decide to forego the nightspot and return to the flat for sex.

The following morning, the come-down kicks in and reality beckons. The prospect of another day at the café and a return to her abusive mother fills Sarah with dread. In a burst of spontaneity Tom invites Sarah to stay in his flat.

Everyday life seems more unbearable for Sarah and she loses her temper at work, snaps at her boss and is subsequently fired. Tom is surprisingly stringent when it comes to work ("Gotta pay to play") so Sarah decides not to tell him of her dismissal. She meets the local drug dealer, Des, who shows her the tricks of the trade and  persuades her to work for him.

Meanwhile, back at home, Sarah's younger sister is bearing the brunt of her mother's alcoholism, which is steadily getting worse. Realising that the escape the drug offers is selfishly absolving her of responsibility, she decides to introduce Tom to her family. Having not been informed of Sarah's mother's drink problem, Tom arrives with a bumper bottle of sherry, which is greeted with drunken enthusiasm.

A harrowing ordeal with a rival dealer prompts Sarah to come clean and give up the new line of work. Tom greets the confession with nonchalance and offers her a pill. While on a night out Sarah receives a distressed phone call from her sister, saying that her mother has tipped over the edge and attempted suicide. Seeking help from Tom, she asks him to come to her family home but he forgets where it is and gives up after touring the town in a taxi.

Sarah decides that this is the final straw and ends the relationship. Tom pleads with her not to, lashing out and blaming her for drawing him in. Sarah leaves and Tom pops another Ecstasy pill and starts dancing, once again ignoring the problem.