Greg sets off to replenish the group's supplies of a vital plant ingredient needed for sunblock, essential in the new climate. During his search trip, he meets a mysterious, attractive brunette, Siren, who appears to have the plant he needs. Through her, Greg finds himself caught up in the sinister activities of a strange sun-worshipping cult, who are determined to put a stop to people they perceive to be 'interfering' with nature and what is seen to be its natural course.