Its the 4th of July. Travis Hall is called into work. Travis works for Seattle SWAT. Ellen Dwyer is Travis's boss. Carly (Pascale Hutton) is Travis's wife. Team members include Ward, Chu (Olivia Cheng), Sophia Gutierrez (Kyra Zagorsky), Benson (Omari Newton), Phil, Hooks (Zahf Paroo) and Phoenix (Lisa Chandler).The DEA enlists the help of the Seattle SWAT to storm a drug cartel's waterfront warehouse to capture cartel members and seize a shipment of drugs. Ward is designated to hold the CCTV camera footage room. Ward guides the team to 2 guards and the SWAT take them down. They locate the shipping container supposed to contain the drugs. Suddenly the compound is surrounded by several armed men. A firefight ensues and when it is over, several DEA agents and one SWAT team member Phil are dead. When the container holding the suspected drug shipment is found and opened, the team is surprised to find a man chained inside. There is evidence that the man has been brutally torture and yet the man is in excellent physical shape. They also arrest another suspect named Diego (Leo Raine). SWAT hacker Elson (Chris Gauthier) figures out that Diego is connected to the drug cartels in Sao Paulo. He also finds that there is no record of their mystery man on the FBI database.Sophia interrogates Diego who refuses to say anything about the mystery man arrested by SWAT. Diego is so afraid and panicked that he starts banging his head on the metal table and kills himself.The terrorists are guided by Lars (Matthew Marsden). Lars receives an anonymous phone call with a demand for $ 50 million in exchange for information on where the SWAT are taking the suspect. Lars gives his phone to his hacker Nicholas to try and figure out where the call originated from. Nicholas finds out that the call originated from the SWAT HQ in Seattle. Simone (Monique Ganderton) is Lars's head of security.After taking him back to SWAT headquarters, Travis interrogates the mystery man. The mystery man says that the events of the day are Pre-determined. He says that soon men claiming to be Federal agents will arrive to take custody of him. If Travis can save him from them, the mystery man promises to help Travis survive what's coming. The mystery man says that he has information in his head worth billions of dollars. Soon, Ellen asks Travis to hand over the prisoner to 2 agents from the FBI. Travis notices that the agents are not carrying official guns and refuse to reveal the prisoners name. Travis attacks them, kills one and imprisons the other agent.The mysterious man calls himself "The Scorpion" (Michael Jai White) and the SWAT team believe him to be a fugitive. They try to move him, but realize that an inside agent is working with the terrorists. The terrorists had surrounded the SWAT HQ and had insider information on all movements in and out of the compound. As soon as Travis tries to move, he comes under a hail of bullets and has to retreat back into the safety of the HQ. Lars had ordered to capture Scorpion alive. Travis asks Ellen to bring the shutters down, locking themselves inside the HQ. Travis Hall (Sam Jaeger), asks Scorpion what he has that the terrorists want. Scorpion reveals himself to be a spy. All calls for backup were intercepted by Simone.Lars asks Nicholas to find a way past the shields. Lars calls Travis on the HQ landline and asks him to surrender. He wants Scorpion. Scorpion tells Travis that Lars runs a Private Militia that runs black operations for any entity. Scorpion agrees to surrender when Simone threatens the family members of SWAT.Lars tells Nicholas that he and Scorpion were partners, but then 5 years ago Scorpion betrayed Lars. Travis makes a plan to lure the attackers to the rear gate to pretend to hand over Scorpion. The rear entrance is over looked by at least 15 windows on the first floor and is a kill zone. Travis thinks the terrorists can be gunned down in that zone. The trap is set but then someone signals to Lars and Simone, who had reached the outside of the HQ, in Morse code, that the rear entrance is a trap. Lars pulls his forces back. Turns out Ward (Ty Olsson), is working with them. Ward frees the captured terrorist Franklin (Mike Dopud) and tells him how to disable the shields from the inside. Franklin kills Ward when he sees Travis and Ellen approaching.The building's lock-down shields are disabled by Franklin and the terrorists storm the building in large numbers. Travis and Ellen kills Franklin. Two SWAT members are killed. Scorpion guns down a hoard of the terrorists and finds a way out through the maintenance tunnel. Hall goes back to rescue Ellen who was separated from the main group. Scorpion and Hall kill the two terrorist leaders Lars and Simone and wait for backup. The SWAT leader, Ellen Dwyer (Adrianne Palicki), and Hall talk and Scorpion hands them a microchip, saying he's tired of running.Hall realizes that Dwyer is the inside agent for the terrorists and a fight ensues. Ellen had mentioned a microchip way earlier and Hall now wonders how Ellen knew that Scorpion was carrying a microchip. She shoots Scorpion and flees with Hall in pursuit. She is caught and arrested and Hall is asked to identify the Scorpion's body.Scorpion uses a dead inmate as a body double, but Hall still identifies him to let Scorpion go free. He returns home to enjoy the fireworks with his family.