The Presence by John Saul (1998, Paperback)

Beyond the sparkling Hawaiian beaches, masked by the deceptive beauty of the rainforest, evil awaits sixteen-year-old Michael Sundquist and his mother, Katharine, an anthropologist who has come to the Islands to study the unusual skeletal remains unearthed on the volcanic flanks of Haleakala, Maui.Yet far below the black depths of the Pacific a mysterious substance snakes through undiscovered fissures in the ocean floor, as nature itself seems to portend the terror to come.Then, with the sudden, unexplained death of Michael's friend, a disturbing truth dawns: the corporation that is funding Katharine's dig has a far greater investment than she ever imagined--an investment in medical terror. And her son may be part of their hideous grand plan... .On Oct-24-12 at 02:01:05 PDT, seller added the following information:Every buyer gets a MyStoreRewards invitation for cash back