The Flannan Isles Lighthouse disappearances refer to a mysterious incident that occurred in December 1900 involving three lighthouse keepers stationed at the Flannan Isles Lighthouse, located on Eilean Mor, one of the Flannan Isles off the coast of Scotland.On December 15, 1900, a relief vessel arrived at the lighthouse to find that the three keepers, Thomas Marshall, James Ducat, and Donald MacArthur, were missing. The relief keeper, Joseph Moore, who was meant to replace one of the three, found the lighthouse empty. The beds were unmade, the clocks had stopped, and there were signs of a meal that had been interrupted. However, there was no sign of the keepers themselves.