Atlantis: The Lost Empire Original and Limited Edition Art (2001)
In 1914, Milo James Thatch (Michael J. Fox), a young linguist and cartographer, works in the boiler room at the Smithsonian Institution. He aspires to follow in his late grandfather Thaddeus Thatch's footsteps to discover the mythical sunken city of Atlantis, but the Institution's board refuses to believe him. Later, Milo is contacted by millionaire Preston B. Whitmore (John Mahoney), a friend of his grandfather, who presents him with the "Shepherd's Journal", an ancient manuscript said to be the key to finding Atlantis. Whitmore reveals that he has amassed a large team and equipment to seek out Atlantis, and Milo has been able to provide the final clue. He offers Milo to join the team, which Milo accepts.
As the expedition starts out on a high-technology submarine, Milo is teased by the senior mission crew, led by Commander Lyle Rourke (James Garner) and his second-in-command Lieutenant Helga Sinclair (Claudia Christian), but slowly is accepted by them. The expedition is met with numerous losses when attacked by a giant mechanical leviathan, but the survivors are able to discover a open-air cavernous route that will lead them to Atlantis according to the Journal. They lose more equipment when they fall into the well of a dormant volcano, but soon escape and find themselves inside a giant underground opening, the city of Atlantis in the center. They are met by the surviving Atlanteans, among them Princess Kidagakash 'Kida' Nedakh (Cree Summer). The crew is brought before King Kashekim Nedakh (Leonard Nimoy), Kida's father, who requests they leave, but Rourke proposes that they are allowed to stay one night to recover before leaving.
Kida, learning that Milo can read ancient Atlantean writings, takes him to several murals to translate. According to Milo, the murals explain that the city and its people are powered by the life-force energy of a huge blue "crystal" called the "Heart of Atlantis", which is stored in the glowing blue crystals that they all wear. Kida recalls the fate of her mother thousands of years earlier, selected by the Heart of Atlantis to protect the city from a titanic tsunami created by the Atlanteans' misuse of the Heart's power. The two return to find that Rourke and the other team members have set plans in motion to capture the Heart of Atlantis by force and return it to the surface. Rourke lethally punches the King to reveal its location, which happens to be beneath the throne room. Rourke, Sinclair, Milo, and Kida descend to the cavern containing the Heart surrounded by the stone faces of past Atlantean kings, which then draws Kida to it. The Heart infuses itself in Kida, disabling power to the rest of the city. Rourke's men place Kida in a container and prepare to transport her to the surface; in the process, Milo's friends abandon Rourke when they realize he is effectively killing the Atlanteans.
Milo realizes that the crystals that the Atlanteans wear still hold energy and use them to power several flying vehicles to stage a rescue along with his friends. They find Rourke in the dormant volcano, ready to hoist Kida up to the surface with a dirigible flying machine. In the ensuing skirmish, the heroes are able to stop Rourke from escaping (with help from a mortally wounded Sinclair, whom Rourke betrays in the fight), with Milo killing the commander in the process. When the dirigible crashes, the volcano becomes active. Milo, his friends, and the Atlanteans escape the erupting volcano with Kida, but soon realize that the entire city is threatened by the eruption. Kida is released from the container, and the power of the Heart of Atlantis activates several giant humanoid figures at the edges of the city, who create a force field that spares the city a fiery fate.
Milo's friends prepare to leave to the surface, while Milo has opted to stay behind with Kida, having fallen in love with her, and to help the Altanteans rediscover their lost technology. Milo's friends return to the surface with numerous treasures, and rehearse a false story with Mr. Whitmore about their experiences, making it seem that Atlantis was never found. They also give him a note containing an Atlantean crystal and a "thank you" message from Milo. The film closes with Milo and Kida completing a stone face of Kida's deceased father, which ascends to join the other stone faces orbiting the Heart of Atlantis. The Lost Empire thrives once more.