La suite de Dead Island reprends dès la fin du premier jeu avec les quatre survivants immunisés. Riptide is set just after the ending of Dead Island, with the four immune survivors. They cannot be infected with the zombie's bites so they can do whatever they want - ex-American football player Logan Carter, rapper Sam B, Chinese undercover police officer Xian Mei, and Purna, ex-police officer - along with international terrorist Charon and native Yerema, asymptomatic patient zero of the Banoi outbreak, landing on a military ship after escaping from the prison island.