Geordi tests an experimental new probe technology that uses a virtual-reality interface to drive its operation. The way it works is that you're hooked up to a VR suit and you operate it as if you were the probe. So when you move your arms to pick up a heavy beam, the probe activates its tractor beam and moves the beam. This essentially allows the user to venture via a VR interface into inhospitable environments. The crew intends to use the technology to retrieve data from a disabled, uninhabitable starship whose crew has perished. (Narratively, the camera shows Geordi as a physical stand-in for the probe, which is the right storytelling decision.)
About this time, Geordi receives news that the Hera, a ship commanded by his mother, vanished recently without a trace 300 light-years away. The search has proven futile and is about to be called off. But then, while hooked into the interface, Geordi sees his mother (Madge Sinclair) aboard the disabled vessel whose data the Enterprise is attempting to salvage with the probe; she says she and her crew are trapped on the inhospitable planet below and she implores him to rescue them.
Obviously, this is impossible. Or almost impossible (as Data attests), since this is Star Trek after all. Geordi searches for answers to clues that cannot be explained, and while everyone believes he has lost objectivity and is seeing what he wants to see, Geordi cannot dismiss what he has experienced and presses on even after it's discovered that the feedback signals from the interface can injure and even potentially kill him in extreme situations. Naturally, Geordi will have to take risks and disobey orders in order to see this thing through.
"Interface," while not great or groundbreaking, is a significant step up from the first two lackluster outings of season seven — much more focused, much less of a mess, and with true character motivation at its core. This is not a matter of Geordi indulging in an obsession of the imagination but rather being compelled to investigate the possibilities he's observed in front of him because he's additionally emotionally vested. As he puts it late in the episode, he can't ignore the possibilities, however remote, because if he doesn't at least try to rescue his mother and the Hera crew, he won't be able to live with himself.
Naturally, Geordi's mom turns out to be a mind-reading alien in danger who needs Geordi's help and has used his mother's image to manipulate the situation. This is not an unexpected development. One wonders why Starfleet crews don't immediately suspect aliens with extraordinary capabilities as the solution to most unsolved mysteries, considering how often it happens.
The introduction of Geordi's mother — not to mention his father (Ben Vereen), who early on gets a scene that I thought hit the wrong note, as if this husband of the missing woman was just another skeptic writing off Geordi's clinging to hope as somehow ridiculous — is the first of several season seven family connections that would eventually come across as the writers grasping at straws. But this is probably the most workable and involving of them. This is a story that tries, in its TNG sci-fi technobabble way, to deal with the nature of loss concerning a missing person who can never be physically confirmed dead. As Geordi stories go this side of "The Enemy," it's a pretty good one.