Tess Black, a fugitive, is the sole survivor of a military experiment that gave her rapid healing powers. When she experiences an unbearable loss, Tesss desire for vengeance opens the way for her possession by Kali, the Hindu goddess of destruction, who has waited millennia for a human body capable of being her perfect avatar. When Kali's age-old nemesis, the buffalo-demon Mahishasura, also finds an avatar, the renewed age of gods and demons threatens all of humanity.