The Stone was discovered by mutant colonists of Valles Marinaris. When Collier Stanton learned about it, lust grew in him. He tricked leader Robert Bloodworth claiming scientific interest. Bloodworth allowed him in the colony and then his team massacred the mutants. Stanton changed his identity and became Marshall Alexander. With the Oracle Stone he was able to see the future and read thoughts, he managed to boost his exploits and build a mogul empire.
In 2039 his daughter Alexis Alexander learned the truth, stole it and left their house; she was persuaded by her boyfriend Rick Logan that they should return it to a legitimate heir. However Logan with his accomplice Johnny Fedora planned to sell it to several figures such as Deacon Hawke, Big Dick Castro and Lowell Percival. Fedora made Alexander think that he would reobtain the stone until Alexander had him killed.
All this was a set up by Thomas Dangerfield, an old associate of Stanton/Alexander. When he learned that Logan did not intend to return the Stone to him, he killed him and took it. Back in Mars, he built a machine that would magnify the impulses of his brain and would allow him to use the Stone.
Meanwhile Nathan Bloodworth notified Alexander that he recovered the Stone, but it was a setup, and he just intended to assassinate Alexander. Big Dick Castro believed that Logan gave the Stone to Hawke and sent thugs to threaten her.
Seeking to find Alexis, Tex Murphy was led to Dangerfield's hideout as he was preparing an experiment of his device that would allow him to manifest his thoughts with the Stone. Tex broke Dangerfield's mechanism and left the laboratory with the Stone as it exploded to pieces. Tex and Alexis decided that Hawke should be the worthy one. As they gave her the stone, she absorbed it and disappeared in a flash of light.