Korean director Park Chan-wook (“Oldboy,” “Lady Vengeance”) and co-screenwriter Chung Seo-kyung cite Émile Zola’s 1867 novel “Thérèse Raquin” as their inspiration for this sci-fi supernatural thriller with black comic threads: a couple kills for love, with her all-seeing stroke-impaired mute in-law and foster mother (it’s not so complicated) as their only witness. Park’s mahjong replaces Zola’s dominoes, but “Thirst” undergoes more than a transplant of details to Korea. The plot is embellished to excess with material that fails to mesh. Sang-hyeon (Kang-ho Song from “The Host”) is a priest who volunteers as a test subject in an experiment to find a vaccine for the lethal, leperous Emmanuel Virus. Only Africans seems immune. By freakish providence, the martyr-minded priest survives. A cult arises to seek healing. But a blood transfusion has turned him into a vampire. At first his blood intake is strictly for medical reasons. Other tastes soon intrude. Secular temptations—Seven Deadly Sins, if you’re counting—include a friend’s wife, Tae-ju (Kim Ok-vin) who tricks her savior into believing her lout of a husband abuses her. She begs to swing in the bloodsucking lifestyle. Gothic melodrama goes nutty with theological handwringing and splattering gore. “Thirst” over-serves. With Kim Hae-sook, Shin Ha-kyun, and Park In-hwan. 133m. (Bill Stamets)