A gothic science-fiction thriller, Observatory details the entangled lives of four people across two centuries. Observatory is set at the Armagh Observatory and Museum for Astronomy and Natural Philosophy, in both 1799 and 1999. Historian Jon McKenna, hired to compile a computerised catalogue of the Observatory archives, finds his life becoming entangled with that of Nicola McLoughlin, assistant astronomer at the Observatory. Together they work to uncover the two-hundred-year-old story of astronomer Archibald Hamilton and his assistant Robert Hogg - man of science, man of God, and revolutionary. The Observatory, a symbol of both science and religion, becomes the setting for a powerful exploration of nationhood and revolution, love and betrayal.