In literature, a plot twist was a literary device used as an unexpected direction that a story's plot could take. Deus ex machina was one such example.
In Tom Paris' opinion, an unexpected plot twist made a story interesting. In 2373, he proposed that the Insurrection Alpha holonovel could have "Captain Janeway" executing all Maquis conspirators after retaking USS Voyager with Paris. Co-writer Tuvok disagreed, citing T'Hain's Dictates of Poetics. (VOY: "Worst Case Scenario")
Upon discovering "Marseilles" kissing a female crewman in sickbay, B'Elanna Torres (playing The Doctor's role in Photons Be Free) described his sending her to engineering so he could give one of her patients a "tonsillectomy" as an "interesting plot twist." (VOY: "Author, Author")