In a pretentious but half-ruined house in County Leitrim called "Ballycloran" lived Larry Macdermot, senile at fifty; Thady, his well-meaning but ignorant son, who acted as his father's agent; and a daughter, Feemy. She considered herself engaged to Captain Ussher, a police officer charged with the detection and destruction of the illegal potheen stills scattered throughout the neighboring mountains, and who was, quite naturally, hated by the local peasants.
Ballycloran had been built by Joe Flannelly of Carrick who, as his bills had never been paid, held a mortgage on the estate. His son-in-law Hyacinth Keegan, an attorney who aspired to become a country gentleman by acquiring the property, threatened to evict the Macdermots and swore to make beggars of the whole family. The tenants hated him almost as much as they did Ussher.
Joe Reynolds, leader of a gang of potheen distillers, plotted to kill Ussher and tried in vain to persuade Thady to join them, but Thady's confidential, servant Pat Brady had become Hyacinth Keegan's spy and stool-pigeon, and succeeded in involving him in the conspiracy. Thady distrusted Ussher thoroughly but was unable to prevent his frequent visits to Feemy, although he suspected that Ussher did not intend to marry his sister. When the Captain was given a promotion that would take him out of the county, Feemy confessed that she was bearing his child and begged him to marry her. He claimed that was impossible, but arranged to take her with him. By chance Thady surprised them as they were departing and, believing that Feemy was being abducted against her will, struck Ussher and killed him. He was tried, convicted of murder and hanged. During the trial Feemy died and their father became completely insane.
Trollope's first novel, suggested to him by the ruins of an estate near- Drumsna, County Leitrim."The Macdermots is almost in the first flight of Trollope... The story is of the simplest, but broadens, as every story ought to do, into the full bounds of its environment.... The characters are all revealed by natural and lively dialogue, and every character has his work to do in the development of the central theme." - Walpole