In an early nineteenth-century England in which there never was a Restoration after Cromwell's Revolution, a party of guests travels to a house-party in Yorkshire to witness the demonstration of the world's first time machine. Michael Laurel, a young painter, is in love with Cecilia Langstrade, and is avid to know whether his feelings are reciprocated-but as he travels to his appointment with destiny, he realizes that he might have a rival in Quentin Hope, an amateur philosopher. Gradually, Michael comes to realize that the entire future of the world might be at stake-and its entire past as well-and that no one who has been invited to Langstrade Hall is irrelevant to the impending catastrophe. But what can he, a mere painter, possibly do to make a difference to the fate of the universe within the labyrinth of time?