The film is about a priest who participates in a medical experiment to find a cure for a deadly disease with traumatic repercussions. "Thirst" stars Song Kang-ho (Sympathy for Mr. Vengeance, The Host) and Shin Ha-kyun (Sympathy for Mr. Vengeance). Involving unusually risque elements, the film also stars Kim Ok-bin (Dasepo Naughty Girls) as leading lady.