At the beginning of the episode, Chief Engineer Geordi La Forge, Commander Data, and Chief Medical Officer Dr. Crusher are testing an interface which allows La Forge to use the VISOR-compatible circuitry in his brain, along with a virtual reality suit to control a probe by remote control. This way La Forge can use the probe to go into areas that would be too dangerous for crew members to enter. When testing is complete, La Forge is informed that the ship his mother commanded has disappeared, and all aboard are presumed dead.

La Forge uses the interface to remotely control the probe and look for survivors on a ship that is trapped in a gas giant's atmosphere. He finds that there is no one left alive on the ship, but believes that he encountered his mother on the ship. Continued use of the probe soon exposes La Forge to unhealthy levels of neural stimulation.

La Forge is convinced that his mother was on board the ship, and wants to use the probe to communicate with his mother. But Dr. Crusher and Captain Picard refuse to allow him to use the interface suit again. La Forge decides to use the suit anyway. While in contact with the probe, he encounters the being who appears to be his mother again, but learns that she is actually a lifeform native to the gas giant. This being talks La Forge into taking the ship closer to the planet, so that she and others like her trapped on the ship can go home.

After he is reprimanded by Picard for his disobedience, La Forge concludes that his mother is in fact dead, and that it had all seemed so real he had thought he had a chance to say goodbye to her.

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Wikipedia