In 1914, a young Irishman named Friend travels to a remote island in the South Atlantic to work as a meteorologist as the previous one passed away. The only other inhabitant of the island is the caretaker of the lighthouse, Gruner, who greets Friend quite coldly. Soon the young meteorologist realizes that the death of his predecessor occurred not from typhus, which is the official explanation, but from the invasion of unknown creatures emerging at night from the ocean.