Retired CIA field operative Bryan Mills (Liam Neeson) attempts to build a closer relationship with his daughter, Kim (Maggie Grace), who lives with her mother, Lenore (Famke Janssen), and her wealthy stepfather, Stuart (Xander Berkeley). While overseeing security at a concert for pop star Sheerah (Holly Valance), Bryan saves her from a violent stalker. As a token of gratitude, Sheerah offers to assess Kim's talent as a singer. Before Bryan can tell Kim, she asks her father for permission to travel to Paris with her best friend, Amanda (Katie Cassidy). He initially refuses, but eventually agrees after Lenore pressures him. At the airport, he learns the girls are actually following Irish band U2 during their European tour, something Lenore knew, but kept from him.Upon arriving at Charles de Gaulle International Airport, Kim and Amanda meet a young man named Peter (Nicolas Giraud), whose taxi-sharing habits act as an opportunity to discover and pass on their details and location. Kim and Amanda go to Amanda's cousins' apartment, only for Kim to find that Amanda's cousins are in Spain. While Kim takes a call to her father, she witnesses Amanda being abducted by strange men in the living room. Kim complies with her father's instructions to hide in a bedroom, but Bryan, knowing she will be found, informs her of it and talks her through the situation. After she is dragged out from underneath the bed, Kim yells the description of her abductor until she is silenced. Her abductor picks up the phone and says nothing to Bryan, who demands that he release his daughter and vows to hunt him down and kill him if he does not. The only response is "good luck", after which the call ends.Sam (Leland Orser), an old friend of Bryan and former colleague, deduces from the killer's description and voice that he is Marko Hoxha (Arben Bajraktaraj), a notorious member and leader of illegal Albanian sex trafficking operations. Informing Lenore about their operations, he warns Bryan that Kim will disappear for good if not found within 96 hours. Using Stuart's private jet, Bryan travels to Paris and investigates the apartment, and later discovers a picture showing Peter in a reflection using Kim's phone. He finds Peter at the airport and tries to capture him, but during the chase Peter is hit and killed by a truck.With his only lead now dead, Bryan turns to an old contact, semi-retired French intelligence agent Jean-Claude Pitrel (Olivier Rabourdin), who now works a desk job at the same agency. Jean-Claude informs him of the local red-light district where the Albanian prostitution ring operates, but warns him not to get involved. However, with help from a hired Albanian translator, Bryan trails and infiltrates a makeshift brothel in an abandoned construction yard, where he finds a young girl wearing Kim's denim jacket. After a brief firefight with the mobsters, he takes the girl to a nearby hotel owned by an old friend. Once there, he administers medication to the girl to detoxify her system.The following morning, Bryan questions the girl and learns of a safehouse where the Albanians keep the abducted girls. Posing as Pitrel, he enters the house pretending to be interested in business. After a brief conversation with some of the mobsters under the guise of a re-negotiation of their business, he recognizes Marko from Kim's description. After Bryan confirms his identity (making him utter the words "Good luck" and asking him about the phone call), Marko attacks but Bryan subdues him. A violent fight ensues, resulting in the deaths of all the gangsters. After the fight, Bryan makes a quick search of the house, revealing several heavily drugged girls including Amanda, who has died from an overdose. Using a makeshift electric chair in the basement, Bryan tortures Marko for information. Marko explains that virgins have high value in the black market and Kim, being a virgin, was sold quickly. Once Marko gives the buyer's name as Patrice Saint-Clair (GÃ©rard Watkins), Bryan leaves him to die from electrocution. Later that evening, Bryan visits the Pitrels after discovering Jean-Claude's corruption, he confirms the corruption, and then wounds his wife and forces him to give him Saint-Clair's location.Bryan attends the auction beneath Saint-Clair's manor. As soon as Kim comes up for sale, he forces Abil, an Arab bidder, to purchase her. While making his way out, he is detained by security and chained to a pipe, but he manages to escape and eliminate everyone detaining him, including Saint-Clair. Before he is shot dead, Saint-Clair informs Bryan that Kim is being taken to a yacht owned by a sheikh named Raman. Making his way to the harbor, Bryan boards Raman's yacht and takes out his guards, before overpowering and killing Abil in a fist fight. He enters the next room, only to find Raman holding Kim at knife-point. Raman attempts to negotiate, but Bryan shoots him in the face without hesitation. They return to the U.S., where she is reunited with her mother and stepfather. Afterwards, Bryan takes Kim to see Sheerah for her first singing lesson and audition.
Output: Question: What is Peter killed by?, Answer: A truck.