Five women share their experiences of being deceived into intimate relationships with undercover police officers. Alison, Lisa and Helen were campaigners in their twenties when they first met their seemingly perfect boyfriends, but creepy clues emerged as their relationships developed. When all three women dug deeper, they discovered they had been spun a web of lies as their perfect activist boyfriends were state agents who had deceived them.

A mutual friend introduces Helen and Alison, and they work out that their former partners must have belonged to a Metropolitan Police squad that infiltrated left-wing groups. No-one is interested in their story and both women are forced to move on with their lives. Seven years later, an online post finally unmasks former officer Mark Kennedy, whose undercover name was Mark Stone.

The women unite to take legal action and share their eerily similar experiences and copycat letters from their former partners. They suspect the officers' tactics were systemic, but the Metropolitan Police resists by citing their Neither Confirm Nor Deny policy in spite of attempts to sue the Met.