Book IV of Man From Atlantis. All the FBI had to go on were a few scraps of paper: one bore the word Felicitos and that rang a bell in Mark Harris's mind. On a perilous rescue mission, the Man From Atlantis sped to a mysterious island off the coast of Brazil. There, in a sophisticated underground laboratory. a deranged woman scientists had concocted a potion that would make the greatest minds on Earth serve her will. Mark Harris was uniquely armed to meet the bizarre adventure that awaited him - an adventure that threatened to take the Earth's intelligence out of the known world to a strange and overpowering new one. Cover art by Vincent Di Fate.