The IRW Kaidor was a vessel serving the Romulan Star Empire in the late 24th century. In 2399, the Kaidor was the closest vessel to the IRW Alth'Indor and attempted to assist the other vessel's crew after receiving a distress call. After arriving, the Kaidor's crew detected an antimatter containment failure, but the Alth'Indor exploded before her crew could be rescued. (ST website: The Path to 2409)