Unexpected challenges are faced by Vicky when 15-year-old little brother, her sister Suzy and Vicky Austin Rob visit their grandfather on Seven Bay Island. Retired Reverend Eaton, her grandfather, generally seems to be seriously ill, but attempts to pretend nothing isn't right. Vicky met the troubled although rich Zachary Gray the prior summer, and he reappears to renew the acquaintance. Still another boy, 17-year-old Adam Eddington, recruits Vicky to help him with a research endeavor, dealing together with a dolphin. Vicky finds she could communicate telepathically with all the dolphin and his partner - and possibly with Adam too