After her husband's death, Elizabeth decides to return to her musical roots, and begins busking with Paul in a plaza overlooking a London ice rink, much to the dismay of her Patricia and Edward. One day, she is spotted by Patrick, who attempted to avoid enlistment during World War II by dressing as a woman and playing drums with the Blonde Bombshells, a supposedly all-female band. Elizabeth performed with the Bombshells when she was only fifteen years old.
The two reminisce, and eventually begin dating. At the encouragement of Elizabeth's granddaughter Joanna, they begin searching for other band members for a reunion concert at Joanna's school dance. At first, they have little success — one has died, another is suffering from dementia. A third, Evelyn is serving time, while trombonist Annie is dedicated to the Salvation Army and refuses to play the devil's music. Elizabeth and Patrick eventually locate piano player and band leader Betty, working in a seaside saloon; she has kept all the band's old costumes, as well as Patrick's drums. The group posts bail for Evelyn and convince Annie to play in exchange for a sizable charitable donation. Singer Gwen, performing in a Wolverhampton nightclub, agrees to sing, although she refuses to rehearse with the group. Evelyn learns that trumpeter Dinah has become an alcoholic living in a secluded manor in Scotland, who agrees to play after Elizabeth and Patrick pay her a melodramatic visit. While in Scotland, Elizabeth learns that the roses painted on Patrick's drum kit indicate how many of the Blond Bombshells he managed to sleep with during the War – he managed to bed all of them, except Elizabeth, who was shielded from Patrick's affections by Betty.
Early rehearsals prove to be disastrous, but encouraged by Joanna, and determined to shine in the limelight one more time, the group steadily improves. On the night of the dance, they are unexpectedly joined by double bass player Madeleine, who had left the band to join the French Resistance and was finally tracked down by Joanna. Gwen arrives just in time, and the Blond Bombshells bring down the house. Gwen notices that Patrick's drum kit is adorned with an additional rose; Elizabeth confirms they have consummated their relationship. As the Bombshells play on, Elizabeth narrates what the bandmates got up to following their successful concert.
The present-day story is interspersed with flashbacks to the band in its wartime heyday, capturing the music and atmosphere of the period.
