Pearl has given up on her dreams of being a journalist after being denied a promotion because of her gender. Joining the WAAF as a radio telephone operator for Bomber Command, Pearl’s new job at RAF Fenthorpe serves two purposes – providing an income for her grandmother, and keeping a close eye on her younger sister, Thea, an instrument repairer on the same base. Pearl befriends Met officer Jenny as well as Australian sergeant Greg, whose Lancashire bomber she guides home safely during an emergency. Pearl’s journalism background doesn’t go to waste, however – a series of thefts from pilots rekindles her investigative fire and she is soon caught up in the mystery. But when all signs point to the perpetrator being her sister, she finds herself up against the clock to prove her sister’s innocence.