London, 1941. The Blitz. When a Royal Navy memo arrives at head office, requesting female recruits to sign up as motorcycle dispatch riders, delivering highly classified orders across the country, three women jump at the chance to sign up for the most dangerous jobs in London.

Olivia grew up riding motorcycles with her brothers, and with them fighting abroad she feels it is her duty to join up. The thrill of adventure draws Ava, but with more enthusiasm than skill, will she learn to navigate the treacherous London streets safely? Having lost her family during one of the first air attacks, Florence knows how important it is to have help arrive on the scene―fast―and so she steps up, outmanoeuvring the men behind the wheel of an ambulance. When Olivia, Ava and Florence meet for the first time they know they have found something all of them need―family.

As bombs fall, decimating the city they love, these three brave women build a sisterhood amid the rubble, facing down anyone―even their own families―who objects to their service. And while romances bloom and fade, their connection grows ever stronger. But none of them dare consider the terrifying reality that one night Florence’s ambulance may be rescuing someone she loves…