A team of deep-sea explorers discovers an underwater society and more in this thrilling adventure from the creator of Sherlock Holmes. Professor Maracot organizes an expedition to examine the area surrounding the deepest pit in the Atlantic Ocean and catalogue wildlife. But a terrifying attack changes the group's plans, cuts them off from the surface, and sends them plummeting into the abyss. A world of surprises awaits them at the bottom of the ocean, including survivors of the lost civilization of Atlantis, fascinating technology and ruins, amazing creatures, and even the face of evil itself . . .