Set in 1939 Britain, working‑class young woman Evie Bishop has earned a scholarship to study mathematics at Oxford — a rare opportunity. But when tragedy strikes and her plan is derailed, she decides to join the Women’s Auxiliary Air Force (WAAF) as an ops‑room plotter, determined to do something worthwhile in the war effort.

Evie is posted to a fighter station on the Sussex coast. There she meets two other WAAFs: shy, insecure May and glamorous, outgoing Jess. Together the three navigate the demands of their new roles — working in a male‑dominated setting, coping with strict officers, daring missions, and the constant danger from German air raids.

As they grow closer — relying on each other for support and friendship — they also face romance, personal ambition and a troubling discovery: the German bombers at the station seem to be one step ahead of expectation, and the girls find themselves entangled in a mystery and danger deeper than mere war‑time routine.