The Children of Dagon are rising... When the sea floor in the Pacific mysteriously drops a few thousand feet, marine biologists, Tom Kinneard and Brett Gilman, accompanied by geologist Ailsa MacDonald, take a manned sub to investigate. What they discover not only re-writes the science textbooks, but also explains the mysterious disappearances of people born on the Lost Day: 29th February. Can they stop the rising of the Children of Dagon, even though one of their number may actually want it to happen?