Original air date: May 10, 1994
Data is on the holodeck, performing a rendition of The Tempest for Picard. As they are musing over the symbolism of Prospero's character, they notice what appears to be a steam train approaching them from out of the darkness. When the computer fails to respond to Picard's order to shut down the program, Data throws them both out of its path, narrowly saving them from being hit.
Outside, Data finds that the train was from a program of The Orient Express, accidentally inserted into their program by an LCARS glitch, so for safety Picard asks him to shut down the holodecks until the problem can be diagnosed.
On the bridge, as the Enterprise is scouting nearby systems for potential colony sites, another computer glitch occurs when the ship suddenly engages its warp drive on a random heading for several moments. Much to the crew's surprise, on further investigation they find that this was no random glitch, but that it saved them from a growing theta flux distortion that was about to destroy the ship — a distortion that the sensors shouldn't have been able to detect in the first place.
La Forge and Data soon discover that multitudes of new circuit nodes have started growing within the ship, forming connections between various systems. It was these nodes that detected the threat to the ship and triggered the warp drive to protect it. Fortunate though this was, the nodes are starting to take control of the ship, raising force fields to prevent the crew from tampering with them. The locus of the nodes is centered on Holodeck Three, so they decide to go there to search for a way to regain control of the ship.
What they find there is a program of The Orient Express, populated by a hodgepodge of anachronistic characters. Data attempts to depolarize the power grid from within the program, but the train conductor turns hostile. With the holodeck safeties off, they have no choice but to back off. The crew also notices that events within the holodeck reflect what goes on in the real world. When the train changes tracks, for instance, the ship changes course.
As the nodes expand and take over more of the ship's functions, Data observes that they resemble a neural net, not unlike a primordial version of his own or that of a humanoid. He concludes that an intelligence is emerging from the ship's processes, and that the holodeck is where its thoughts and instincts are expressed. The crew therefore decides to return there, but with a less confrontational approach, in hopes they can regain control of the ship without destroying the nodes. Picard reasons, "If the ship is truly an emerging intelligence, then we have a responsibility to treat it with the same respect as any other being."
Meanwhile, Cargo Bay 5 has become a new center of activity. A bizarre object is growing there, fueled by the ship's power. The ship approaches a nearby white dwarf star and starts drawing vertion particles from it. Picard notes that the holodeck train is heading for a place called "Vertiform City," so this must be its destination. The object in the cargo bay starts growing rapidly from the particles, but only briefly, as the star is exhausted of particles in only a matter of seconds.
La Forge's scans of the object while it was growing suggest that it is a new lifeform that the ship is attempting to create, but without vertion particles, it will not survive. The ship bolts off towards the next nearest white dwarf, but in its haste has drawn all power to the engines, including from life support, so the crew will not survive long enough to reach it.
On the holodeck, Data convinces the conductor to give him control of the train, which he uses to redirect the ship to a much closer nebula. La Forge detonates a modified torpedo within, creating enough vertion particles that the ship's offspring can become self-sustaining. It flies off into space, and all remaining signs of the emergent intelligence vanish from the ship.
After things have returned to normal, Data visits Picard to invite him to a small recital he is putting on of a scene from The Tempest. Picard quotes a line from the scene, "O brave new world, that has such people in it," and notes its appropriateness. In parting, Data asks the captain why he allowed the ship to create and send off the new entity, when its nature was unknown.
Picard replies, "The intelligence that was formed on the Enterprise didn't just come out of the ship's systems. It came from us. From our mission records, personal logs, holodeck programs, our fantasies. Now, if our experiences with the Enterprise have been honorable, can't we trust that the sum of those experiences will be the same?"
Tropes featured:
- A.I. Is a Crapshoot: Subverted. The ship doesn't turn evil, but rather develops its own primitive instincts that drive it to create a sort of offspring of itself. It has no interest in the crew except when they are helping or hindering it in its goals. (Though it does shut off life support and divert its power in its desperation to save its offspring.)
- Anachronism Stew: The ship's "subconscious", as visualized on the holodeck, has a few characters clearly out of place, such as a Medieval Knight in Shining Armor.
- Anthropomorphic Personification: The holodeck characters from the Orient Express hologram may be considered as this to each system of the Enterprise.
- Arc Symbol: A multicolored knot of lines seen in a puzzle and on playing cards in the holodeck simulation. Through the first few acts of the episode, the crew try to figure out what it means. It's ultimately revealed to be the alien creature's physical form.
- Everything Sensor: Subverted. The ship's sensors shouldn't have been able to detect the theta flux distortion because they weren't designed to.
- Explosive Instrumentation: Geordi's console explodes and knocks him to the deck. Only his Plot Armor saves him from serious injury (or worse).
- Hyperspeed Escape: The ship's helm laid in a course and the warp drive automatically engaged once the sensors detected the theta flux distortion. Except none of those systems are designed to interface together like that.
- Journey to the Center of the Mind: The holodeck is useful to the crew for its symbolic representation of what the ship is trying to do.
- Lightning Can Do Anything: Data theorizes that the magnascopic storm encountered prior to the episode provided the spark of life for the emergent intelligence.
- Negative Space Wedgie: We get two for the price of one this episode, though neither appear on screen.
- There's the magnascopic storm, encountered off screen before the episode and the presumed spark that created the nodes.
- Then there's the theta flux distortion, supposedly invisible to the ship's sensors, which would have destroyed the ship if the emergent intelligence hadn't warped away from it.
- Patrick Stewart Speech: Picard closes the episode with such a speech, to explain to Data why he felt confident that the emergent offspring, having been born from the Enterprise logs and personal records, would take on the same benevolent character as the crew.
- Reality Subtext: Picard's discussion of The Tempest and its End of an Age themes mirrors the imminent end of this series, and Star Trek: Deep Space Nine and the then-upcoming Star Trek: Voyager assuming the mantle of the "current" Star Trek shows. Additionally, Picard's mention of Prospero's performing "one final creative act before giving up his art forever" referenced writer Joe Menosky's having written the script under the assumption that it would be his last time working on the franchise— he would, in the event, return for much of the run of Voyager, and briefly on Star Trek: Discovery.
- Sci-Fi Writers Have No Sense of Scale: One of several examples of the writers not quite getting that a ship as big as the Enterprise has a lot of oxygen for the crew to breathe. Even with life-support failure, everyone should still survive for over a day.
- Short-Lived Organism: The Enterprise exhibits peculiar behavior. The crew determines that the ship's computers are becoming sentient, and have embarked upon assembling a construct in one of the holodecks. Once this construct is teleported outside the ship, the ship returns to normal, having attained sentience for only the one episode, just long enough to produce an "offspring".
- Shout-Out to Shakespeare: The episode starts with Data playing Prospero from The Tempest. At the end, Data chooses to perform the scene in which Miranda first encounters other humans for his recital, which he decided was topical after the events of the episode. Picard can't resist quoting a line when he learns.Picard: "O brave new world, that has such people in it."
- What Happened to the Mouse?: To this day, no part of the canon has ever touched on this episode again. The fate of the emergent lifeform, or the fact that the Enterprise would probably have wound up being spacedocked for the rest of its existence with every scientist they could throw at it crawling through its innards trying to figure out how and why it became sentient and technologically reproduced over the course of a week, is never even brought up.
