Detective Tom [Sean Patrick Flanery] and his partner Ryan Alba [Greg Serano] have spent the last three years unsuccessfully trying to locate the Lion, an international hit-man that has always eluded their grasp. The tip comes from an anonymous man who claims to be the father of the Lion and believes that it is time for his identity to be revealed. On Christmas Eve, the streets are deserted as most people are at home with their families. They believe that they've found his location via a tipster but instead find Tom's wife Kelly [Michelle Greathouse] tied up in a basement filled with explosives, surrounded by a black outline. The Lion [Joe Pantoliano] calls Tom and commands him to kill Kelly or risk the entire house blowing up and killing everyone inside. Tom had entered the house with a large team of agents and everyone's life is in danger. The Lion has CCTV cameras installed in the basement and warns Tom that he can see everything. The Lion asks Tom to shoot at a red heart taped to Kelly's chest, behind which is the trigger mechanism for the bomb, directly behind the heart. Any attempt to evacuate the house or rescue Kelly will result in everyone getting blown up and the Lion will not accept any substitutions, as he wants Tom to suffer for messing up the Lion's network in the Southwestern United States. Tom has 3 minutes and 25 seconds to make a decision. His only mercy is that Tom may turn out the lights in the basement. With no other option, Tom has the lights turned off and he shoots and kills Kelly. Amy [Julianne Flores] is Ryan's daughter. At the time of the incident, Tom was planning to start a family with Kelly.
Eight years later a grieving Tom is now retired and living in Mexico. As he's had past experiences dealing with the Lion, FBI agent Isabel Ordonez [Carmen Serano] travels out to persuade him to help track down and capture the Lion. Tom is the only person who has ever spoken to the Lion and Isabel needs Tom's help identify the conversation between the Lion and his associate, confirming the address for their meeting. She shows him evidence that the Lion will be meeting associates at a nightclub. Tom refuses but secretly copies down the address so he can take his own revenge for Kelly's death. Amy is Ryan's daughter. At the time of the incident, Tom is planning to start a family with Kelly. He refuses the offer to help but keeps the information, a quiet seed of vengeance now blooming in him. The Lion plans a new strike and Tom senses a very personal motive behind the attacks.
At a nightclub, Tom is initially unsuccessful at identifying the Lion even as the Lion walks past him to meet with an associate. The Lion, who is aware of Tom and the FBI's presence, receives his requested materials from his associate before killing the associate and detonating a bomb to cover his escape. Tom quickly follows after the Lion and after an extended chase scene, the Lion manages to subdue Tom and is about to cut his throat when an unmarked police car enters the alley, forcing the Lion to abandon Tom and make his escape. The FBI agent driving the car, Hops [David House], mistakes Tom for one of the Lion's associates and tries to arrest him. Hops is later corrected on this, and Tom is brought on to assist the FBI's task force along with his old partner Ryan, who is now part of the FBI. The FBI believes that Kaplow is targeting Senator Cordero [Fredrick Lopez], who used to be a DEA agent.
The Lion disguises himself as a hotel janitor, to observe a hotel in Albuquerque. As janitor, the Lion uses a chemical agent to damage the hotel floor and then goes in as a mason to fix the floor, but now installs the floor with an explosive cement and a trigger chip in it. The Lion has messaged the FBI to pay him $100 million as ransom for not carrying out any further hits, else he plans to destroy the city. Tom believes that all this talk of ransom is a distraction as the Lion is never interested in the money. Tom believes that the Lion is in town for a very specific reason.
Tom and Isabel figure out that a cleaning crew employee has not reported to work for 2 days, and the same guy was at the nightclub which the Lion bombed. The missing janitor worked at the hotel which the Lion was visiting. As Tom and Isabel reach the house of the janitor, they find it bugged and the Lion calls Tom threatening to blow the house up. Tom and Isabel escape and realize that the Lion is playing with them. It turns out the hotel that the Lion was working on is where Ryan's daughter Amy works as a bartender. The Lion calls Amy and tells her that he has the entire hotel on lock-down, has installed bombs inside the floor and can detonate them remotely. He has Amy announce to the guests that they are in a hostage situation. The Lion wants his money and increases the price to $200 million and detonates the explosives at the hotel after asking Amy to leave. Tom and the team review the CCTV footage around the hotel and check for all hardware stores that sold fertilizer in cash over the last month. The Lion's true identity is revealed (David Kaplow) and he kidnaps Ryan's daughter in an attempt to have Ryan assassinate Cordero in exchange for his daughter's safety. He's successful, as Ryan does as he's instructed, but Ryan is in turn shot and killed by Cordero's bodyguard. Eventually Kaplow makes his big move and bombs the FBI headquarters, during which time he kidnaps Ordonez. Tom makes his way to Ordonez's house, where he sees that Kaplow has tied her up and strapped a bomb to the agent. The two men fight and Kaplow manages to force Tom to handcuff himself. A policeman arrives on the scene but is killed by Kaplow, who is wounded in the process. Kaplow then escapes the house and detonates the bomb, believing that this is the end of Tom and Ordonez. However, Kaplow then receives a call from Tom stating that they are not dead, and that Kaplow's bullet proof vest is rigged to bombs. Finally, Tom detonates the bomb and Kaplow explodes inside the police car.
