Jemima Pardon, a paramedic with a daft name and chronic asthma, has never had much in the way of good luck. The only things she attracts are traumatic jobs, and no one wants to work with her for long.

But when Jem bumps into devil-may-care police officer Rosie Jones, her fortunes seem to be changing. Rosie is bright and funny, and she doesn't mind that Jem can't go far without her inhaler.

Things are looking up, until a suspicious death draws Jem and Rosie into an investigation that spirals beyond their control. As torrential rain floods the city, they face a battle to survive if they're ever going to have a chance at finding love.