In Britain, a virus has swept the country, turning people into zombies. The virus has spread from a breakout from a prison in the south of England. A joint British-American special forces squad goes into the quarantine zone to extract Dr. Julian Raynes, a scientist who is meant to have the possibility of making a cure. There are four possible locations he might be in. The group, made up of Captain Stanton, Lieutenant Perez, Paige, Rodrigo and several others, enter the first location by assault craft on the river. They encounter the first zombies and discover that they are not like the normal zombie genre and are more intelligent, capable of hand-to-hand combat and utilizing objects. The first location is overrun by zombies and they manage to fight their way out and find some combat vehicles that they use to get to the second location - a set of high rise flats.The flats are overrun with zombies and they make it to the room they need on the nearly top floor, the scientist not there again, but disaster soon strikes, when the biggest guy on the team, Jacob, is bitten during a struggle. Jacob commits suicide via gunshot to avoid zombification. They spot vehicles full of zombie soldiers who have maintained their military capabilities. The squad hide out amongst a pile of dead zombie corpses, but Private Bernstein is captured and taken away on a truck. They follow the vehicles using the tracking signal from Bernstein and discover a zombie army camp where there are a large number of zombie soldiers fully kitted out in CBRN hazmat suits. They discover their missing soldier being held in a container with other survivors - including two female civilians and Dr. Raynes.After rescuing everyone in the container, they are confronted by the zombie soldiers and a firefight occurs with many survivors being killed by the zombies shooting them. After managing to get away, they interrogate Raynes. Meanwhile the squad's commanding officer, Major General Smith, discusses the outbreak with the rest of his command staff and it turns out that his own son is infected and that they are still experimenting on other zombies. After taking shelter in a bunker, Paige admits to her boyfriend, Rodrigo, that she became infected during an earlier fight when some contaminated blood got in her mouth. He shares a passionate kiss with her anyway, knowing he will be infected like her. They stay behind from the group and head off into the countryside. They also discover that the surviving girl, Alicia, might be immune to the virus.Stanton, Bernstein, Perez, and Alicia arrive at the pickup point where Smith tells them that he has had to kill his son and there is no cure. Smith blamed Raynes and wanted vengeance. Smith shoots Raynes and gets back to the helicopter whilst a firefight ensues between his security detail and the survivors. Perez is injured and it is revealed Bernstein was blackmailed by Smith to gather intelligence due to his parents being held captive. Perez remains behind to fight a horde, but is outmatched and devoured. Stanton and Alicia are captured by the prison group and it turns out that Alicia is the daughter of the leader of the rioters, Jimmy, who died after escaping earlier in the film. Jimmy was earlier revealed to have at least partial immunity from the virus. While Stanton is checking Alicia's bit it is revealed that she has scars from being bitten previously. He knows from the journal and a previous conversation that Jimmy was partially immune, and correctly deduces that Alicia is totally immune. Stanton decides to try to get to the free zone and secure an alliance from a group of armed survivors who are near the border. They meet the survivors and discover Private Bernstein with them. Stanton explains the military's plan to bomb the quarantine zone and the survivors agree to help him cross the border.At the border they fight a very large group of zombies and are joined by the prison gang who decided to aid them. Once they get through to the border crossing, Smith arrives and tells his men to kill everyone but a fight ensues between him and a zombified Stanton, who manages to defeat the General. During the aftermath, Stanton is given a mercy killing by Bernstein, and Alicia is extracted from the quarantine zone.(copied from Wikipedia)