Covering the years between 1907 and 1914, Strumpet City follows several characters through the nightmare years of the "Dublin Lockout," when the Catholic Church sided with the industrialists to smash Irish labor's first substantive steps towards unionizing.
Using the real-life labor organizer Jim Larkin (Peter O'Toole) as the dramatic lynchpin for the various stories, Strumpet City juggles several storylines to give an overall view of the terrible poverty and misery that afflicted the working poor of Dublin. The central story revolves around Mary (Angela Harding), a young domestic who comes to work for the wealthy, oblivious Bradshaws (Edward Byrne and Daphne Carroll). Once Mary meets handsome, kind foundry worker "Fitz" Fitzpatrick (Bryan Murray), she immediately falls in love, and the couple make plans to save enough money to eventually marry.
Mary, distressed at the way the Bradshaws shuttle off their devoted housekeeper Miss Gilchrist (Mairin D. O'Sullivan) to the poor house when she can no longer work, decides to leave the insensitive Bradshaw household and marry Fitz.
Unfortunately, historic events conspire to make the young couple's life one of continued want and anxiety. Fitz's involvement with the union frequently keeps him out of work, when he and his fellow workers go out on strikes. And once he works his way up to being foreman of the foundry, he's suddenly caught between the obligations of his new job (and to his employers), and with his union brothers who expect him to walk out with him.
The other main story of Strumpet City involves the difficult path of Father O'Connor (Frank Grimes), a snobbish Catholic priest who, in a misguided attempt to ease his conscience, leaves his wealthy parish to work among Dublin's most wretched tenement houses. Utterly unsuited to work among the poor (for whom he has a barely concealed disgust), Father O'Connor is greeted with open scorn by his superior, Father Giffley (Cyril Cusack), a troubled alcoholic who has spent too much time among the poor -- the poor who can't be helped with spiritual guidance alone.
Father O'Connor's friend, Protestant businessman Mr. Yearling (Denys Hawthorne), frequently challenges O'Connor on his beliefs and where his sympathies lie - which is almost always with the factory owners and with the well-to-do.