The film opens on a winding mountain road. We see the Tour de France peloton arduously making its way up the steep incline. The camera then pans up an impossibly steep and winding grade, where several miles ahead of the other riders we see RAMBO pedaling a modified Harley-Davidson. He seems to be barely exerting any effort as he makes his way up the hill.
"I think it's about time I took a shortcut," RAMBO says.
He veers off the road, and pedals his bike directly up a vertical cliff-face. Below him in the distance, we see the peloton explode.
As RAMBO rides up the cliff, the camera pans over to reveal THE GENERAL sitting in a sidecar which was not attached to RAMBO's bike a moment ago.
"Rambo, I know you're retired, but I've got a mission only you can accomplish," he says.
"No thanks, General," RAMBO replies. "The only mission I'm interested in is bringing honour and repute back to the world of international cycling."
"You don't understand, Rambo, it's your old enemy Baron von Veidelstein, the evil oil tycoon. He's captured your friend, Bigfoot, and won't let him go unless we cut down all the rainforests in the world," THE GENERAL says.
RAMBO appears to consider this for a moment.
"Bigfoot saved me from a POW Camp when we were in the war. I owe him my life. And the rainforests are where my many animal friends live. Count me in, General."
We transition to a 20-minute montage of RAMBO pedaling his bicycle past a variety of landmarks, which he is obviously poorly green-screened in front of. He pedals past the Great Pyramids, the Tower of London, Mount Rushmore and a still photo of the moon landing before arriving at the shores of an ocean. THE GENERAL is still seated in the motorcycle's sidecar.
"This is the end of the line, Rambo," THE GENERAL says. "Von Veidelstein is at his base in the South Pole, and not even you can make it all the way across the ocean on this motorcycle."
"Time to call an old friend," RAMBO says.
He whistles, and a dolphin appears in the water.
"My goodness, Rambo!" THE GENERAL yells. "Is that?"
"Yes," RAMBO replies. "It's Air Bud, the smartest shark in the world."
At this point in the film, it becomes uncomfortably clear that the screenwriter has confused the canine star of popular Disney films with a marine mammal, and, in turn, a marine mammal with a cartilaginous fish.
"Go Air Bud, go!" RAMBO yells as he leaps atop the dolphin. "Air Bud" begins to skip across the surface of the water as jetski noises emanate from him.
We cut to a shot of a steamy, Southeast Asian jungle. A caption at the bottom of the screen reads, "The South Pole". A lone militiaman paces back and forth, keeping lookout. He takes a fortune cookie out of his pocket and absentmindedly cracks it open.
From offscreen, we hear the whine of a jetski growing closer and closer. The militiaman looks up from his fortune cookie and peers into the distance, trying to locate the source of the sound. Finally, RAMBO enters the frame riding atop Air Bud, who slides to a halt, throwing RAMBO forward. RAMBO flies, arms outstretched, straight through the militiaman's torso leaving a perfectly circular hole. The militiaman falls to the ground in slow motion, and we see a close-up of his fist unclenching to reveal the fortune hidden in his cookie.
RAMBO then sneaks through the jungle to a walled compound. He scans the compound through binoculars, and sees a large group of well-armed militiamen standing guard.
"I'll have to use all of my skills to sneak past them unnoticed," RAMBO says.
He then pulls two M60 machine guns from behind his back, and runs full-tilt toward the guards, screaming at the top of his lungs and firing indiscriminately. The guards flee in terror as he mows them down. This merciless slaughter continues for about 45 minutes unabated.
Finally, RAMBO breaks into the compound. He is confronted by BARON VON VEIDELSTEIN, who is a large, stereotypical German Hun character wearing a monocle and a spiked helmet. VON VEIDELSTEIN holds RAMBO at gunpoint.
"Greetings Rambo. I assume you've come for your friend, Bigfoot," VON VEIDELSTEIN says. "We could fight one another like barbarians, or we could settle this like gentlemen."
He gestures toward a chessboard.
"I know you fancy yourself a chess player, Rambo. It's said you're the best in the world. Well I intend to put that to the test. I propose we play one game, winner take all. For each piece you lose, I shall kill an orphan. But if I lose, Bigfoot goes free."
RAMBO stares at the chessboard, then back at VON VEIDELSTEIN, then back at the chessboard. After a moment, VON VEIDELSTEIN bursts into flames.
"You lose," RAMBO says.
RAMBO then makes his way to a holding cell within the compound, where he finds BIGFOOT. He releases the grateful Sasquatch.
An anonymous young man approaches and puts a hand on RAMBO's shoulder.
"Well done, Rambo. You made short work of Von Veidelstein."
"I sure did," RAMBO replies. "And I also finally solved that mystery we were working on. It turns out you were a ghost the whole time."
The young man gasps and then suddenly vanishes. RAMBO and BIGFOOT laugh and high-five. The frame freezes as Def Leppard's "Pour Some Sugar On Me" plays over the credits.