It is 'Wakes Week' in the Lancashire town of Hindle, the annual holiday when the cotton mills close down.
Mill girl Jenny Hawthorne meets Alan Jeffcote at Blackpool Amusement Park. He is the son of the self-made proprietor of the mill where she works. Alan has been unable to persuade Beatrice Farrar, his fiancée, to join him on holiday, as she has to go to London with her father, on business.
Suddenly brought together and encouraged by the holiday atmosphere, Alan and Jenny leave their friends, and go off together to Llandudno for an illicit weekend. Jenny leaves her friend Mary a note asking her to send a postcard from Blackpool to Jenny's parents to establish an alibi for her whereabouts. Unfortunately, Mary is killed on a coach outing, and when the unposted card eventually reaches Chris Hawthorne and his wife, their suspicions are aroused.
On her return to Hindle, blissfully ignorant of Mary's fate, Jenny maintains the deception until her parents' cross-questioning makes her realise that Mary has been killed before she could send the postcard. Saddened but still defiant, she admits how she really spent the holiday. Hawthorne is further upset when he learns that her weekend partner was Jeffcote's son. Hawthorne and Jeffcote had once worked side by side at the mill, but Jeffcote was ambitious and had prospered, eventually owning the mill, while Hawthorne had progressed no further than being his most trusted employee. The men had always remained friends, despite the difference in their social station.
Hawthorne is too fond of his daughter to be really angry, but his wife vents her spleen on Jenny, all the while thinking how the girl's behaviour - and its possible consequences - might be turned to their financial advantage.
Hawthorne has the difficult task of telling Jeffcote what has happened. Though very disappointed, Alan's father decides that Alan must marry Jenny and give up Beatrice, despite Sir Timothy Farrar's money and mills. Jeffcote had always hoped that one day they would be amalgamated with his own. He calls a meeting of the two families to discuss what to do next. Jenny and Alan remain silent while their mothers are at loggerheads, and Jeffcote reiterates his determination to have his wishes carried out. Jenny suddenly interrupts the proceedings to enquire whether her wishes in the matter of her proposed marriage are to be considered. Then she and Alan leave the room. She tells him she does not want to marry him at all and that, in missing the opportunity of becoming the wife of the heir to the Jeffcote mills and money, she is not making any sacrifices. She explains that, just as she was Alan's little 'fling', he was hers - and she had as much right to enjoy herself as he did.
Alan is hurt at first, but has to admire Jenny's nerve. He returns to a forgiving Beatrice, while Jenny happily leaves her home and her mother's anger to resume life and work at the mill.
