In Amsterdam, American backpackers Paxton (Jay Hernandez) and Josh (Derek Richardson) and Icelander Óli (Eyţór Guđjónsson) meet Alexei (Lubomir Bukovy), a Russian man who tells them about a Slovak hostel filled with American-loving local women. The backpackers board a train to Slovakia, where they meet a Dutch businessman (Jan Vlasák) long enough to be unnerved by his bizarre behavior.
Upon arriving in the small village, the backpackers check into the local hostel and find themselves sharing a room with Natalya (Barbara Nedeljáková) and Svetlana (Jana Kadeábková), two attractive, single women who entice the backpackers to a spa and a disco before sleeping with them.
The next morning, Óli is missing. A young Japanese backpacker named Kana (Jennifer Lim) also reports that her friend Yuki (Keiko Seiko) has disappeared. An MMS photo sent from Yuki's phone shows Yuki and Óli beneath a smokestack of an abandoned factory, with the word Sayonara written beneath it. Unbeknownst to Josh and Paxton, Oli has been decapitated and Yuki tortured, and (presumably) killed.
Paxton and Josh decide to leave Bratislava with Kana the following day. They spot a man wearing Oli's jacket at a museum of medieval torture relics. Paxton later notices that in the MMS photo of Oli, Yuki and the smokestack is faked. Later that night, while partying with Natalya and Svetlana, Paxton and Josh succumb to the effects of alcohol. Josh stumbles back to the hostel while Paxton passes out in the disco's storage room.
Hours later, Josh wakes up handcuffed to a chair in a dungeon-like room surrounded by power tools and weapons. The Dutch businessman enters in a leather apron and gloves and begins torturing Josh, drilling him in his pecs just above his nipples. After he is done, the Dutch Business man sits down and talks to Josh, explaining his unfulfilled dreams of being a surgeon. Josh begs to be released, the businessman then cuts Josh's Achilles' tendon and lets him crawl towards the door before finally murdering him.
Across town, Paxton awakens and returns to the hostel to find both Josh and Kana missing. In his room are a different pair of beautiful women inviting him to a spa, eerily similar to Natalya's and Svetlana's offer from before. When the local police chief (Miroslav Táborský) proves unhelpful, Paxton locates Natalya and Svetlana and demands to be taken to an "art show" where he thinks his friends are.
They drive to a factory on the outskirts of the town where inside, Paxton sees the Dutch businessman cutting up Josh's dead body. He screams at Natalya, who laughs at him, and he is then ambushed by thugs who drag him past cells filled with other backpackers being tortured by various clients.
Paxton is taken to his own cell and restrained to a chair, joined minutes later by a German client (Petr Jani) who tortures him. Distracted by Paxton's ability to plead for his life in German, the client puts a ball-gag in his mouth and tries to kill him with a chainsaw, but before he can begin Paxton starts throwing up, either out of fear or because the gag was choking him. Due to his ball-gag, he starts to choke on his own vomit, and the client quickly removes the ball-gag, probably to stop Paxton dying before he could kill him.
He then continues his torture with the chainsaw, but inadvertently saws off Paxton's handcuffs along with his ring and pinky finger before slipping on the ball-gag which he just threw on the floor. The client drops the chainsaw on his own leg and severs it. Paxton breaks free and shoots the client in the head with a gun on the weapon counter. When the guard comes to check on the situation, Paxton shoots and kills him before escaping dressed in torture gear. He hides in a nearby room to avoid capture from other guards, where he finds a collection of victims.
He hides under a pile of body parts before being taken to a room where he sees dead bodies being chopped up by a butcher for cremation. Paxton kills the butcher with a hammer, and escapes to the surface where he then peers outside to see police officers conspiring with the factory men.
Paxton dresses himself in the clothes of a client, pulling a glove over his mutilated hand, and discovers a business card for Elite Hunting, now revealed as a secret, worldwide, murder-for-profit organization that charges ascending rates for Slovakians, Europeans, and most of all for Americans. An American businessman (Rick Hoffman) arrives and believing Paxton to be another client, discusses his intended victim and asks Paxton whether to kill her quickly or slowly.
Paxton advises administering a quick death, but the American businessman disagrees and decides to resort to torturing her, leaving behind a no longer needed firearm before exiting. Paxton steals the firearm and escapes to the courtyard when he hears a woman scream. Unable to ignore it, he returns to the factory and kills the American, now in the middle of burning Kana's face with a blowtorch. Kana's right eye is hanging out of her injured face -- Paxton cuts it off and they run outside.
Paxton and Kana steal a car and head to the railway station, spotting Alexei, Natalya and Svetlana on their way from the original hostel. Paxton vengefully runs them over, killing them both. He later runs into the gang of kids and notices that he is in the same car that he was driven in to the "art show", which has a bag of candy in it.
The gang then kills the people chasing Paxton, having been bribed with the bag of candy. At the railway station, Kana notices the disfigured reflection of her missing eye, and, unable to live with her hideous scars, throws herself into the path of an incoming train, distracting the guards and allowing Paxton to escape aboard another train.
Once aboard, Paxton hears the familiar voice of Josh's torturer, the Dutch businessman. As the train stops in Vienna, Austria, Paxton follows him to a public restroom and throws the Elite Hunting's card under his stall. When the Dutch businessman reaches down to pick it up, Paxton grabs his hand and, using a scalpel, cuts off the same fingers he lost during his escape. He then breaks into the stall and nearly drowns the Dutch businessman in the toilet bowl, allowing time for him to recognize Paxton, before slitting his throat, killing him. Paxton then leaves to board another train out of Austria.