An American fashion photographer, James Garner as Ben Morris, travels to Guadagil, a remote village in South America, to photograph model Alison Duquesne for a lipstick ad featuring the shade "Pink Jungle." She arrives soon after Ben, escorted by Michael Ansara as Raul Ortega, from the tourist board. Within minutes of landing, the helicopter that brought them is stolen, leaving Ben and Alison stranded in the village.
Ben is challenged by Colonel Celaya, Fabrizio Mioni, a security officer eager for a promotion to the capital and certain that Ben must be a spy for the American government. A quick search of Ben’s baggage reveals only camera equipment and lipstick, doing little to calm the suspicions. Ben and Alison make their way to the town bar, where they are joined by Ortega, who looms over the situation and raises the stakes. Meanwhile, two thugs assault and kill the helicopter pilot and—shockingly—Ortega is shown to be their leader.
To escape their boredom, Ben and Alison rent a car and head toward the nearest town, only to be stopped at gunpoint by the same man who hijacked the helicopter. He forces them to take him along. The hijacker is the boisterous South African adventurer Sammy Ryderbeit, played by George Kennedy. He boasts that he and his partner have a map to a fabulous diamond mine, but they need $2,000 to fund the expedition.
In a bar in town, Ben and Alison meet Stopes, the partner in the diamond scheme, portrayed by George Rose. Also present are Ortega and his men, and the couple begins to doubt the truth of the diamond tale. When Stopes is murdered in his hotel room, suspicion falls on Ben, Alison, and Sammy, and the local police close in. Forced to act, Ben agrees to finance the expedition as a means for him and Alison to slip away, a plan observed by Ortega and his men.
On the trail, the trio encounters McCune, Nigel Green a devious Australian who claims to be Stopes's former partner and asserts that he alone has the actual map. He covertly swaps Sammy’s map for his own and tries to seize leadership of the expedition, offering others a share in the mine. Although distrust runs high, they press on. Each man displays impressive marksmanship as they rest and prepare, increasing the tension.
Conflict erupts as tensions flare and the men jockey for control. McCune attempts to coerce Alison, prompting a confrontation with Ben. In a private conversation, Ben and Alison admit that they have fallen in love. That night, McCune sneaks away with the supplies and the maps, leaving the others to face a deadly thirst and exposure. They pursue him, and when he misroutes them, it gives them a chance to close in. McCune is shot dead by Sammy just as the trio closes in on the map.
A helicopter is heard and seen overhead, and Ortega is found at a tent counting diamonds. The helicopter returns with more diamonds, and the intruders from the air converge on the campsite. In the ensuing firefight, Ben, Alison, and Sammy prevail and capture Ortega. Sammy then flies Ben, Alison, and the captured Ortega back to Guadagil, claiming he knows a buyer who will pay in American dollars. But as soon as they land, Sammy seizes the diamonds and disappears, leaving the others surprised by his duplicity.
Ortega turns out to be an underground leader long sought by local authorities, and the town is so relieved by his arrest that they overlook the trio’s earlier misdeeds. Ben seeks to depart, and the jubilant Colonel Celaya, who has taken credit for Ortega’s capture, cannot arrange their exit but does apologize for his earlier misjudgment of Ben. Ben then makes a private move, converting his camera into a two-way radio and contacting his government handler. The revelation emerges that Ben is not merely a photographer but a U.S. government agent sent to quell a revolution led by Ortega. In a final twist, Ben tells his contact that Sammy’s help should be rewarded with a safe exit for him, ensuring the mission’s conclusion remains a delicate balance of duty and deception.
