About a week following the harrowing events of Hostel, we find Paxton (Jay Hernandez) living in isolation with his girlfriend, Stephanie (Jordan Ladd). The couple has a heated argument as Paxton refuses to inform the authorities about the Elite Hunting Club in Slovakia, fully aware that a massive conspiracy lies in the shadows. Tragically, the next morning, Stephanie awakens to a gruesome sight: Paxton's headless body is slumped at the kitchen table, their cat licking the blood from his neck. Meanwhile, in Slovakia, a mysterious package is delivered to Sasha (Milan Kako), the owner of Elite Hunting. The ominous reaction of Sasha's dogs hints that the package likely contains Paxton's severed head.
In Italy, a group of American art students—Beth (Lauren German), Whitney (Bijou Phillips), and Lorna (Heather Matarazzo)—are persuaded by Axelle (Vera Jordanova), a nude model they are sketching, to join her on a holiday at a luxurious spa in Slovakia. The four characters travel by train to a quaint Slovakian village and check into the local hostel (the very same one from the previous film), where the desk clerk (Milda Havlas) uploads their passport photos to an auction website. Various bidders around the globe, including hotshot businessman Todd (Richard Burgi), compete for the chance to claim Whitney and Beth as their victims for a terrifying murder-vacation.
As night falls during the village’s lively "Harvest Festival," Lorna stumbles upon the fact that Beth has inherited a fortune from her mother. In a twist of fate, Stuart (Roger Bart), Todd's passive best friend, strikes up a conversation with Beth. Meanwhile, a drunken Lorna is whisked away for a boat ride by the charming yet sinister Roman, who suddenly abducts her with the help of two accomplices. A local man attempts to ask Beth for a dance, but she declines, leading to his ominous comment: "I could have helped you." Just moments later, the clerk reassures Beth, saying, "He won't bother you anymore." Although Beth and Whitney head toward safety, Axelle volunteers to search for Lorna.
The following morning, the trio goes to the local spa for some blissful relaxation. As Beth unwinds amidst the soothing hot springs, she dozes off, but her tranquility is short-lived. Lorna, now bound and gagged, is suspended upside down in a dark room, where the sadistic Mrs. Bathory (Monika Malacova) enters, strips, and begins torturing her with a scythe, bathing in her blood until she ultimately slits Lorna's throat.
Simultaneously, Todd and Stuart arrive in Slovakia, where the audacious Todd pressures Stuart to embrace their sinister plan as an escape from their mundane lives. Despite his reluctance to kill, Stuart ultimately agrees to accompany Todd to the Elite Hunting venue. Meanwhile, Beth awakens in solitude, realizing her belongings have been stolen, and soon finds herself surrounded by men in a threatening manner. In a bid for freedom, she scrambles over the walls of the spa, only to be intercepted by the "Bubblegum Gang"—a group of vicious street children. Just as they are about to overwhelm her, Axelle and Sasha appear, driving the gang away. Sasha's wrath is revealed when he punishes the children by executing one on the spot, asserting dominance over his "business."
After being brought to Sasha's grand estate, Beth recognizes the horror as she stumbles upon severed heads, including Paxton's, confirming her fears about Whitney and Lorna's fates. Captured and brought to the hideous factory, she witnesses Whitney struggling against her restraints while tortured by an old woman. Whitney manages to escape for a brief moment but is quickly recaptured.
In a shocking turn, Stuart enters the room where Beth is held captive, horrified at the tools meant for torture. He divulges the grim details of the Elite Hunting organization, a secret society catering to the wealthy who lust for murder and mayhem. Although initially conflicted, Stuart’s sociopathic tendencies arise as he begins to lash out at Beth, once again projecting his frustrations onto her.
Whitney finds herself in Todd's clutches, tormented by his clumsy excitement with a power saw. In a horrifying moment, he accidentally injures her, triggering a moment of clarity for him as he realizes the grotesque reality of their actions. Unwilling to fulfill his contract, Todd is murdered by the guards for his defiance. The remains of Whitney are put on display for prospective bidders, with a cannibalistic client shown indulging in the flesh of their previous acquaintance, Miroslav, while others partake in equally vile acts.
Ultimately, it is the deranged Stuart, under the guise of torturing Beth, who finally succumbs to madness and accepts the invitation to kill Whitney. However, in a thrilling reversal of power, Beth manages to gain the upper hand and chains Stuart, twisting the horror against him. She confronts Stuart for the code to their cell, driving a needle through his ear when he refuses. With knowledge in hand, she strikes a harrowing deal with Sasha, making her escape one driven by bloodshed as she decisively cuts off Stuart’s genitals, tossing them to the dogs and leaving him to bleed out, echoing her earlier torments.
As the tension subsides, Beth is marked with an Elite Hunting tattoo, officially inducted into the dark world she sought to escape. However, in a chilling twist, she finds herself free but under strict orders of silence regarding the organization. In the film's chilling final moments, as Axelle is lured into the woods by the Bubblegum Gang, Beth seeks vengeance, surprising her and beheading her in a moment of poetic justice. The film concludes with a haunting image of the gang joyfully playing soccer with Axelle's severed head, encapsulating the cycle of horror that ensues.
