Perry Berg is president of Benthic Marine and a passenger aboard The Benthic Explorer, a 450-foot research ship endeavoring to drill into, and sample for the first time, the earth's magma core. Also onboard are the lovely Dr. Suzanne Newell; ex-navy commander and present submersible skipper Donald Fuller; and navy-cum-Neanderthal divers Richard Adams and Michael Donaghue. It is this cast of characters who, with the reluctant Perry, dive to the stilled drill site in order to make repairs. En route, they are sucked into a defunct undersea volcano and deposited into an otherworldly wonderland.