G.I. Joe: The Movie

Falcon reaches the Slaughter House but he finds that the renegades have already had breakfast and Slaughter puts him to work on his assault course. Later Slaughter contacts Duke who tells him that Flint's unit have so far had no luck in finding the missing Joe's in the Himalayas, but he wants Slaughter's unit to invade Cobra HQ and try to find out if Cobra know where Roadblock's unit is.
 

Slaughter tells the renegades that they are to infiltrate the Terror Drome on Cobra Island, which all of the renegades think is suicide. Slaughter tells them to think of it as an extra tough training exercise, which Falcon responds to by saying they should make it even tougher by not taking any weapons with them. Slaughter takes this idea seriously which the Renegades aren't that happy about.
 

In a surprise move to try and confuse Cobra, the Joes move the B.E.T. into a civilian security lab as they think that Cobra would never think of looking for it there. But one of the crew helping move the B.E.T. is actually Baroness, who runs off to tell everyone at Cobra-La.
 

Later on that night the Renegades arrive at the Terror Dome on speedboats and thanks to Mercer knowing the lay out of the base, they sneak in though an air vent and find Serpentor talking to a batch of his troops explaining to them their mission.
 

Serpentor tells everyone that he now knows where the Joes are keeping the B.E.T. and that they are going to attack the base and air-lift it out of there, all for the glory of Cobra-La. Red Dog asks Mercer what Cobra-La is but he says that he's never heard of it. Slaughter believes him and tells Falcon to contact G.I. Joe HQ whilst the Renegades go off to get weapons and set a bomb to destroy the Terror Drome.
 

The Renegades start a battle with the Cobra troops as Slaughter gives the bomb a countdown of 15 minutes before it explodes, and since it's been placed in the armoury, it should take the entire Terror Drome with it. Meanwhile Falcon tries to contact G.I. Joe HQ but he can't get through to anyone and warn them that Cobra is on the way. He's then captured and questioned by Serpentor, but he won't tell them anything.
 

With only a few minutes left on the bomb's time, the Renegades head back towards Serpentor's throne room and free Falcon as the base goes up when the bomb detonates. All of the Renegades escape and head back the way they came in their speedboats, but Slaughter tells them not to count on this being the end of Cobra.
 

Serpentor has survived and gathers together the combined forces of Cobra and Cobra-La to attack the Joes and get the B.E.T. They start an assault on the civilian security lab and the Joes counter-attack, but a new kind of enemy is there which stops the Joe's vehicles with weird alien weaponry.
 

The battle gets worse for the Joes as Serpentor deploys the Marauders, huge worm like creatures which tear through the Joes and then batter down the walls to the building holding the B.E.T. Nemesis Enforcer rips open the dome which is holding the B.E.T. and Destro goes to inform Serpentor that they have got what they came for.
 

As Destro takes the B.E.T. away the Joes continue to fight Marauders as Falcon, Slaughter and the Renegades show up to join the battle, but Serpentor destroys Slaughter's tank and then goes after Falcon.
 

Duke sees that his half-brother is in trouble and runs towards the explosion, but another explosion prevents the other Joes from following him. Seeing Serpentor, Duke starts to fight him and Serpentor grabs one of his serpents to throw straight at Falcon, but at the last second Duke stands in front of him to take the hit, which plunges straight into his heart.
 

Serpentor tells Falcon that his half-brother's sacrifice will be in vain and he runs off to the B.E.T., which is flown out with on of Cobra-La's large alien ships. Later the Joes crowd around the injured Duke, who tells Falcon that he won't be there to look after him any more. He tells Falcon to make him and his country proud and Falcon promises that he will. Duke then goes into a coma.
 

The B.E.T. is returned to Cobra-La where Serpentor presents it to Golobulus, and they turn it on. The B.E.T. sends out energy into space and the spore pods start to ripen. Golobulus shows everyone something called a time worm, and tells them that once the worm has completed it's journey, the pods will explode and the spores will rain down on the Earth.
 

Later on Dial-Tone sees a huge energy reading coming from somewhere in the Himalayas and realises that it must mean that the B.E.T. is somewhere up there due to it being the only thing that could create such a large reading. The Joes prepare to mobilise and the rawhides want to go to but Beachhead says that they lack experience and Hawk tells them to stay behind to guard the base.
 

In the Himalayas Roadblock and Cobra Commander are now lost, mainly because Cobra Commander has become a proper snake now and can barely say anything other than "I was once was a man". He then turns violent and attacks Roadblock, and they fall down the side of a ledge and straight into Flint, Lifeline and Iceberg who were looking for him. Cobra Commander slithers off as Flint checks that Roadblock is OK.
 

Flint contacts Falcon at the G.I. Joe HQ and tells him to pass him through to Hawk. But Hawk has already taken a group of Joes straight to the Himalayas to fight Cobra-La and get the B.E.T. back. Roadblock is then patched through to Hawk and tells him to pull out as the place is filled with killer plants which will capture them all as they did to his unit.
 

The warning comes too late though as Hawk and all of the other Joes get captured. Flint then shows the Rawhides how Cobra Commander has been horribly mutated by the spores and that if they don't stop the B.E.T. from being used the same fate will happen to everyone else on the planet. Falcon says there's no way that that's going to happen and leads everyone out to the Himalayas.

Duke was meant to die, originally. The writers for the G.I. Joe cartoon were fed up with complaints that their show wasn't a realistic war series as characters never die, so they decided to kill off their lead character. But after Optimus Prime died in The Transformers: The Movie, and the huge negative backslash it received, a last minute change was made to the G.I. Joe movie so Duke just goes into a coma, despite having had a snake through the heart.

In the Japanese dub of the film, Duke actually does die.