Roman Catholic priest Sang Hyun volunteers in an experimental study of a killer virus. After a series of supposedly life-saving blood transfusions, he’s the only survivor among 50 volunteers, he’s covered with horrifically ugly blisters, he coughs up blood, he’s gained an acute sense of smell, and, oh yeah, he’s become a vampire.

It’s hard to tell if religion is being praised or slapped down in the Korean language film “Thirst.”

It focuses on the Roman Catholic priest Sang Hyun (Song Kang-ho) who, wanting only to do good for mankind, volunteers in an experimental study of a killer virus. Among his thanks, after a series of supposedly life-saving blood transfusions, are that he’s the only survivor among 50 volunteers, he’s covered with horrifically ugly blisters, he coughs up blood, he’s gained an acute sense of smell, and, oh yeah, he’s become a vampire.

Writer-director Park Chan-wook (“Old Boy”) sticks with most of the standard rules of vampire lore, but conveniently leaves out the fear of crosses – living death would have been pretty difficult for a priest if crosses got in the way. And he adds a stronger than usual sexuality along with a pretty bizarre and very dark sense of humor to it all.

The complex plot, filled with all kinds of back story, brings the priest together with the family of an old school friend, Kang-woo (Shin Ha-kyun) who has recently married Tae-ju (Kim Ok-vin), who years ago was taken in by Kang-woo’s family as an orphan.

Complications set in. Tae-ju tells the priest how unhappy she is in her marriage; the priest feels a first flicker of attraction toward her; she makes it clear that she’s long had feelings of desire toward him; and after a steamy scene of kissing, licking, biting and love-making, he tries to tell her that he’s a vampire. Things don’t go very well from there.

Where’s that dark sense of humor? Here’s a hint: The priest is a good man who is struggling with this affliction. He knows that he could never kill anyone, even though his lust for blood is tearing him apart. His solution is to visit comatose hospital patients – as a priest, of course – and when no one is looking, slurping from IV tubes that are flowing with blood. No matter how depraved that sounds, it comes across as funny on the screen.

Song Kang-ho, who also starred in the horror-comedy “The Host,” is superb as the conflicted priest, managing to get viewers to think of the character as both repulsive and sympathetic at different times. But Kim Ok-vin, as his forbidden love interest, gets to play with a much wider character arc, going through changes that won’t be revealed here but are thrilling to watch.

The film turns into a tale of sickness, jealousy, infidelity, murder, an ever-increasing amount of black humor, and more than one vampire. There are gory scenes that are most definitely not for the squeamish, and there are scenes of haunting beauty, such as a segment showing two vampires, who have acquired the ability to fly, gracefully hopping from rooftop to rooftop, accompanied by romantic string music.

The biggest issue in “Thirst” is its study of the difference between good vampires and bad vampires, between those that manage to get by without hurting anyone and those that gleefully go for the throats of their victims.

Vampire films are quickly regaining the popularity they once enjoyed, with both “Twilight” and “Let the Right One In” drawing some big box office numbers last year, a “Twilight” sequel around the corner, and a big screen adaptation of “Dark Shadows” in the works. But “Thirst” stands out among all of these. It’s a spectacularly weird movie.

THIRST  (R for graphic bloody violence, strong sexual content, nudity.) Written by Park Chan-wook and Jeong Seo-Gyeong; directed by Park Chan-wook. With Song Kang-ho and Kim Ok-vin. 3 stars out of 4.

The Patriot Ledger