Plot
At the airport in El Paso, Texas, five U.S. Army sergeants meet up with Major Paul Hackett, the leader of the clandestine Zombie Unit, composed of soldiers reported to be killed in action and on temporary assignment under Hackett for the duration of a secret mission.
Jack Benteen is a tough Texas Ranger. His best friend from high school is Cash Bailey, a former police leaker who has crossed into Mexico and become a major cocaine trafficker. Bailey tries to bribe Benteen to look the other way while sending major flake shipments to the U.S. When Benteen refuses, he is left with a warning by Bailey: Look the other way, or die trying.
Benteen and his friend, Sheriff Hank Pearson, are ambushed by Bailey's men at a gas station outside of town, and Pearson is killed in the shootout; Benteen realizes Bailey set them up. Two of Bailey's men escape the shootout and try to steal Hackett's vehicle but are killed.
The Zombie Unit arrives in town tracking Bailey. When they attempt to rob a local bank, the getaway is inadvertently foiled; one member, Luther Fry, is killed and two others - Buck Atwater and Declan Patrick Coker - are caught and detained by Benteen in the process. Benteen discovers the men are listed as dead in all official records, and their ammunition is the kind issued to members of the Army Special Forces.
Benteen is confronted at his home by Major Hackett, who tells him they were robbing the bank in order to get Bailey's money and a safety deposit box containing accounts on all the drug money deposited in his name. Bailey was a previous government informant under Hackett's management, who turned rogue, and Hackett is leading an off-the-books mission to eliminate him and the documents linking him to the U.S. Government.
Now understanding the full story, Benteen teams up with the soldiers and crosses the border into Mexico to track down Bailey and end his snow running operation. At Bailey's hacienda, they are joined by Benteen's girlfriend Sarita Cisneros, who was once Bailey's woman and has followed Benteen into Mexico.
At an Independence Day festival, Benteen confronts Bailey while the soldiers prepare to attack Bailey's private army - telling them to "[terminate] with extreme prejudice," including Benteen. Hackett is caught murdering Bailey's accountant by his right-hand man Larry McRose. It is revealed that there never was a sanctioned mission - Hackett was actually Bailey's former partner who Bailey stopped cutting in, and now he is trying to get his money while covering up his own involvement in the drug trade. The orders to the "Zombie Unit" were all forged by Hackett, who intends for them to die at the mission's conclusion.
Atwater warns Benteen about Hackett's orders to be shot on sight and tells Benteen to go for himself. The town erupts into a massive gunfight, with the surviving Zombie Unit fending off both Hackett and Bailey's men, as Benteen and Sarita escape in a Jeep. McRose guns down Hackett and is killed instantly, along with the rest of the Unit, among them are Charles Biddle, Monday and Chub Luke, a coke smuggler and the brother of T.C. Luke, who was killed by Benteen in a tavern several days earlier.
Afterwards, Benteen and Bailey confront each other again in a duel. Benteen pleads with Bailey to surrender, but Bailey refuses, fires at Benteen, and Benteen returns fire, killing Bailey. Benteen strikes a deal with Bailey's right-hand man, Lupo, allowing him to take over the local dope business in exchange for being allowed to leave Mexico unharmed with Sarita; Lupo advises Benteen to return the favor for him someday, as the two walk off to an uncertain future.
