The best sequel will be the next one, starring a 90-year-old Harrison Ford.

It bodes not well for Dial if that's true. Pity.

Discussing the Indy sequel that didn't get made --

Prologue: Nevada
The story opens in Nevada, where a semi-retired Indiana Jones and his Russian emigre workmate Yuri Makovsky are working in an Anasazi site. One night, Indiana lends his truck to Yuri to travel to a nearby village, but he sees Yuri meeting with other men and heading for a different direction, so Indy decides to follow the convoy and discover their intentions.

After entering a secret US Army base in the desert, Indy discovers that Yuri is actually a Soviet agent and foils his plans to purchase an amount of uranium and a mysterious package from two corrupt American scientists. However, after a chase through the compound, he is captured by the Soviets, put in a car's trunk and left to die in a fake village during a nuclear test. Indy escapes using a refrigerator as shelter and is rescued/arrested by the US Army.

Marshall University and New York
After a long interrogation, Indy is released by the US government, but an FBI agent is assigned to watch him anyway, as the government still suspects him of having communist sympathies. He also loses his job at Marshall University and decides to forget the shock by drinking. Once completely drunk, he decides to break into Marcus Brody's museum during the night and steals some of the objects he brought in, like the Chachapoyan Fertility Idol.

Indy is caught by the FBI agent after him, but a Soviet agent (one of the ones Indy saw earlier in the military base in Nevada) kills the FBI man and attempts to kill Indy too. Somehow, Indy recovers control over his actions and is able not only to escape the Soviet, but also to kill him. After searching the Soviet's coat, Indy finds the key to one of Grand Central Station's lockers and flees there avoiding the police, who believes him to have killed the FBI agent.

In New York City, Indy finds a crystal skull in the cabinet and instructions to meet somebody in a hotel room. Indy finds a gangster there that gives him a fake passport, a plane ticket to Peru and further instructions to meet somebody else there. As it is revealed later, the man supposed to use that plane ticket was Yuri, who beats up the gangster.

Peru
In Peru Indy meets Marion, now wife of the charismatic Hungarian nobleman and archaeologist Peter Belasko, who is still angry with Indy for abandoning her. She needs the crystal skull to find the mythical city of Los Dioses, a place in the Peruvian rainforest where (according to the legend) wishes can come true. Many expeditions had tried to locate it before but failed. The last one was headed by an old friend of both, Professor Vernon Oxley, who has been missing since then.

Belasko claims that the Nazca Lines are actually a code that, interpreted correctly, can help locate the city. Indy and Marion rent a plane to photograph the figures. But during their mission, they are attacked by another plane piloted by Yuri. A dogfight follows, after which both machines crash in the Peruvian jungle. Indy and Marion are rescued by a mysterious German doctor named Felix von Grauen who lives among a tribe of Hovitos. He returns them to Belasko's camp, but Yuri is captured by Peruvian soldiers. Yuri avoids being hanged by promising the ruthless Peruvian dictator President Escalante that he will help him to use the skull and find the city. Von Grauen is revealed to be working for Escalante when he sabotages Belasko's expedition the next day, and Yuri is able to make radio contact with a Soviet military airplane.

Back in Belasko's camp, Indy discovers a completely insane Oxley imprisoned in a truck, caged like an animal. Belasko is using him to interpret the Nazca symbols and draw the itinerary of the expedition. But at the same time Indy makes this public to the rest of the expedition, Escalante's men attack the camp and take them prisoner... and shortly thereafter, Soviet commandos called by Yuri show up. All want the skull. As a result, a Mexican standoff follows until it is suddenly broken by the attack of giant, hungry army ants.

Everyone flees the ants, most (like Belasko) jumping into a nearby river. Indy and Marion take the truck where Oxley is caged and are chased by both Soviet commandos on horseback and the Peruvian army in jeeps. The truck falls into the river and is chased by Peruvian inflatable boats. Just as the boats are about to take the truck, it falls over four waterfalls. Miraculously, the people on the truck survive, while almost all the others die. Back on land, Oxley flees by vine-swinging through the jungle while Marion and Indy are captured again by Escalante (who is also holding Yuri, Belasko and three of Belasko's men prisoner). However, Belasko steals a machine gun and kills all the remaining Peruvian soldiers. Immediately, he reveals that he is also a Soviet agent, which upsets Marion.

"Los Dioses"
Belasko finds the entrance to the lost city, but before entering it, he is betrayed by his Peruvian aide Porfi. Everyone is tied to a jeep rigged with a bomb set to explode, but they are rescued by Oxley at the last minute. When they enter the lost city of "Los Dioses", they find Porfi crazy and his two partners dead.

Finally they reach the Main Temple, which has a complex aqueduct and still-working electric golden wires, despite its antiquity. In a chamber, the group finds artifacts from all of the world's ancient cultures, including an Egyptian skiff. And in the main circular chamber, they find thirteen headless skeletons made of crystal. The skull "tells" Indy which skeleton it belongs to and Indy places it on its shoulders.

Immediately, a mechanism activates revealing thirteen alien mummies sitting on thirteen thrones, each one in front of one of the skeletons. A supernatural voice asks about the other skulls. When it is told that no one knows about them, the voice becomes angry.

The voice claims to be from one of the alien beings that long time ago took over Earth and gave birth to all ancient civilizations and religions. In order to be kept alive, the aliens demanded human sacrifices and built the skeletons to keep their 'souls' there once their corpses decayed. This voice says then that it is time to grant a wish to those five members of the groups with the greatest desire: Peter Belasko, Yuri Makovski, Von Grauen, Escalante and Indiana Jones.

Von Grauen wishes to restore the "greatness" created by the Nazis, and a fake Adolf Hitler takes his heart apart, Escalante wishes to be feared by everybody, and he is converted in a poison frog, Belasko wants to know everything, and his brain melts due to the excessive knowledge. Indy demands Marion. Indy is pardoned then. While the other men die, the alien belonging to the activated skeleton slowly comes to life.

But Indy saves Makovsky. The alien, angry and needing a fourth human body to complete his restoration, takes Oxley by the neck and begins to suck his life force. Indy shoots the alien with a rifle and kills him, saving Oxley's life.

The Main Temple begins to fall apart then and the remaining survivors flee through the aqueduct in the skiff. A giant UFO, buried under the whole city, begins to take flight... until it stops, crashing into the jungle, producing a nuclear-like mushroom cloud. Safe on the river by then, Indy beats Yuri and tells him to stay away from his country in the future.

Epilogue: Washington, D.C.
Back to the States, Indy is cleaned of all suspicions and receives the Congressional Medal of Honor from US President Dwight D. Eisenhower for his help in "destroying a Communist plot that caused a nuclear explosion in the jungles of Peru." The movie ends with Indy marrying Marion and dancing, while a drunk Henry Jones Sr. sings Frank Sinatra's Fly me to the Moon and Oxley moves the cutlery with the power of his mind.