Picard assigns Geordi to use his new capability of using his VISOR as a link between his brain and a mechanical probe to rescue the science vessel U.S.S. Raman, which has become trapped inside the turbulent atmosphere of an unusual gaseous planet. While Geordi prepares for his mission, Picard receives distressing news from Admiral Holt. The U.S.S. Hera, which is commanded by Geordi's mother, has disappeared without a trace, and has essentially been given up for lost.

Picard breaks the news to Geordi, and Riker volunteers to take over the Raman mission to allow him time to grieve. But Geordi refuses to give up hope that the Hera will be located. He insists on handling the mission himself, reminding Riker that the device is specifically designed to work with his VISOR inputs. Soon, via the probe, Geordi is inside the Raman, where he discovers the bodies of seven crew members. Then, suddenly, flames flash in front of him and he cries out in pain, prompting Data to quickly disconnect him from the interface. When Geordi is examined, everyone is shocked to discover that his hand has been seriously burned.

Back in Sickbay, Beverly deduces that Geordi was injured because the neural tolerance levels established between Geordi and the probe were too high. His response to the input created a feedback loop, which caused the burns. Despite the realization that the technology is not foolproof, Geordi is still eager to return to the Raman and salvage the science vessel's data. Before he returns to the Raman, Geordi speaks with his father, who provides details about his mother's funeral service. Dr. La Forge's words agitate Geordi, who tells his father he still believes his mother will be found. Later, he returns to the Raman through the probe. As his eyes adjust to the light, he is shocked to see his mother, Silva La Forge, standing in front of him.

First, Silva is confused, not realizing the metal probe she is looking at is her son. However, once Geordi explains the situation, their relationship is established and Silva begs her son to take the ship down to the planet's surface, because her friends are dying. As mother and son approach each other, a sudden and violent shock surges through Geordi, and the interface deactivates. However, Picard is unwilling to risk Geordi's life for a mission he doesn't believe has a real purpose, and refuses to allow another interface. Frustrated, Geordi decides to defy orders and go it alone, and Data chooses to help him despite the trouble they will certainly meet.

Geordi's mother tells him her ship is trapped in a warp funnel — corroborating Geordi's own theory. Meanwhile, Picard and Beverly hurry to the lab, where Picard insists that Geordi stop. Geordi refuses and presses on, but is surprised to encounter no ship or warp funnel. His mother reaches out for him, and he is racked by sudden, burning shocks that only end when she is pushed away as if by an unseen force. With the danger to Geordi's life increasing, the crew prepares to disconnect him. But before they can, Geordi makes a surprising request to take the Raman further down, telling them that it was not his mother speaking, but a member of a group of lifeforms who have been trapped on the Raman and will die if they are not returned to the planet's lower atmosphere. He continues to descend as the ship is rocked by turbulence, until the alien posing as his mother reverts to its true appearance as a flame, states they are now safe and says goodbye. Geordi is revived after the Raman explodes to face an angry Picard, who soon softens and expresses sorrow that Geordi didn't find his mother. Geordi thanks him and replies that, in a way, his experience helped him to say goodbye.