In Panama, a team of Army Rangers led by Master SergeantNathan West engage in a jungle training exercise that involves live ammunition. Sergeant Ray Dunbar emerges from the jungle carrying wounded Second Lieutenant Levi Kendall. The two men are pursued by Sergeant Mueller, who is shooting at them, and Dunbar kills Mueller in self-defense. Although no other bodies are found, West's team are presumed dead. Dunbar refuses to talk to Military Police investigator Captain Julia Osborne and insists on speaking to a fellow Ranger from outside the base, drawing an "8" on a piece of paper. The base commander Colonel Bill Styles calls in his friend, and an experienced interrogator, DEA agent Tom Hardy who is also an ex-Ranger, and assigns him to aid Osborne. West was infamous for being a ruthless, tough-as-nails sergeant. One of the trainees, Jay Pike, has earned West's wrath for not following the orders, and may have staged the murder. Kendall, son of a Joint Chiefs of Staff general, is a homosexual and claims West hated him and may have ordered a "training accident" on him. He claims West died when hit in the back with a white phosphorus grenade. When Pike confessed to the crime, Dunbar wanted to turn him in; a firefight ensued, in which most of the trainees were killed. Dunbar says Kendall is lying. Mueller and Castro were illegally selling prescription drugs and West became aware of their drug dealing. Mueller used Pike's grenade to kill West, then tried to pin the blame on Pike. A firefight broke out and several trainees were killed. Dunbar claims that Dr. Peter Vilmer, an old friend of Hardy and Osborne's former love interest, supplied the drugs and falsified drug tests so that soldiers came out clean. After confessing to the crime, Vilmer is placed under arrest. Styles orders Osborne and Hardy to not talk to Kendall again. They disobey and interrogate Kendall once more, but he suddenly becomes much worse, bleeding and vomiting blood. Before he dies, he draws an '8' with his own blood. Hardy reveals the conversation he had earlier with Styles. There is rumored to be a group of ex-Rangers in Panama, trained under West, who turned rogue and became drug dealers. They call themselves Section 8. Styles is furious; he relieves Osborne of duty and asks Hardy to leave. He considers the investigation closed and the CID transport from Washington will arrive to take Vilmer and Dunbar away. Vilmer accidentally reveals that 'Dunbar' is actually Pike, and Hardy takes Pike off the plane at the last moment. In Pike's new story, West learned about the main operation going on at the base: cocaine smuggling. He confronted the Rangers and threatened to turn them in to authorities. After a brief firefight, West and the other trainees were killed. Pike then took Dunbar's dog tags and carried Kendall to the extract point. He then gives Hardy, Osborne, and Styles the number of a crate where Vilmer had stowed cocaine. Hardy then confronts Styles alone. Styles was behind the drug-dealing operation the whole time. When West reported the operation to Styles, he ordered Mueller and Kendall to kill him in the jungle and then poisoned Kendall afterward to keep him quiet. Styles tries to bribe Hardy, then turns his weapon on him, but is killed by Osborne, who was eavesdropping on their talk. As the investigation is concluded, Osbourne suspects that Hardy may be involved, because he served with West and hated him, and because Section 8 contains West's former trainees. She sees Pike sneaking into Hardy's car and follows them into Panama City, where they enter a doorway with a big eight-ball hanging above. In the building, she is greeted by West and the rest of the team—Castro, Dunbar, and Nuñez, who Hardy reveals as his 'colleagues'. Section 8 is a black-ops anti-drug unit led by Colonel Tom Hardy, and the "insane mercenary" story is a cover to spook the cartels. The agents infiltrated the base under false names to investigate cocaine trafficking, and discovered Mueller, Kendall, and Vilmer were responsible. West, not realizing Styles was also involved, informed him of drug dealing. The training mission ordered by West was a covert Section 8 operation to circumvent Mueller and Kendall, faking West's death in order to transfer him to Section 8. Hardy had been called to the base by the coded message to confirm Styles' and Vilmer's involvement. Impressed by her work, Hardy offers Osborne a job in the unit.
The movie earned $11.5 million in its opening weekend, ranking behind Head of State, Bringing Down the House, and The Core. It grossed $26,793,311 in the US by the end of its theatrical run. Reviews were mostly negative. The film received a rating of 21% from the critics aggregated by Rotten Tomatoes, with the critics' consensus: "Basic gets so needlessly convoluted in its plot twists that the viewer eventually loses interest." Roger Ebert gave it one star out of four and wrote that it was "not a film that could be understood", and that "It is all smoke and no mirrors. If I were to see it again and again, I might be able to extract an underlying logic from it, but the problem is, when a movie's not worth seeing twice, it had better get the job done the first time through". Leonard Maltin's Movie Guide gave it two stars out of four and wrote that the film "keeps adding layers of confusion so that it becomes less interesting as it goes along! The final "twist" seems to negate the entire story, like a bad shaggy-dog joke."
