It is 1943, and three very different girls are longing to do their bit for the war effort. Frances – her life of seeming privilege has been a lonely one. Brave and strong, stifled by her traditional upbringing, she falls for a most unsuitable man. Prudence – timid and conventional, her horizons have never strayed beyond her job as a bank clerk in Croydon until the war brings her new experiences. Rosalind – a beautiful, flame-haired actress who catches the eye of Frances's stuffy elder brother, the heir to an ancestral mansion. The three become friends when they join the band of women working the canal boats, delivering goods and doing a man's job while the men are away fighting. A tough, unglamorous task – but one which brings them all unexpected rewards.