The USS Enterprise-D is on a mission to catalog young planets in the Pleiades Cluster. Along the way, they have been instructed by the Federation to check on the terraforming colony on Velara III, as they were behind schedule. Captain Picard calls down to the station, and after a minute or two of no answers from the planet, Director Kurt Mandl finally responds.
The director insists there is no need for them to pay a visit as they are back on schedule. Counselor Troi senses that he is extremely nervous about something, especially when Picard insists that an away team be sent down to have a look around. Troi, Commander Riker, Lieutenant Yar, Lieutenant Commander Data, and Lieutenant La Forge beam to the facility.
They are greeted by hydraulics specialist Arthur Malencon, biosphere designer Luisa Kim, and Chief Engineer Bjorn Bensen. Outside the complex is Velara III’s dark, windswept desert, a hostile place, which Kim tells them to remember; in a couple of decades, she plans for it to look like a Garden of Eden. Kim apologizes for their director’s rudeness. She points out that they don’t get many visitors and mentions that Dr. Mandl has been under stress lately.
Kim offers a look around, proudly explaining their amazing procedure of taking a lifeless planet and converting it into a class M environment.
Afterwards, La Forge and Data can’t help but go to Malencon at the controls for the hydraulic probes. He mentions he has been having problems with the servos that control the probes. La Forge offers assistance, wondering if the high saline content of the soil is disrupting conductivity, but Bensen quite abruptly puts that theory down. Mandl finally enters – although initially apologetic about his abruptness in their earlier conversation – appears gruff and moody. He reminds Malencon of their tight schedule and sends the tech off to work in the laser drilling room.
Mandl directs the away team’s attention to a schematic diagram of their planning; everything is specific and exacting.
Suddenly, Troi senses terror and announces that Malencon is in trouble. A warning siren sounds and the group runs to the hydraulic station. As they approach, they hear the blasting of a drilling laser and cries of pain. The door to the room is sealed; they try to force the hatch when the laser blasts and screams abruptly stop.
Upon opening the door, they find the room is a complete mess and spot Malencon, so badly injured he probably cannot be saved. In the center of the room a large drilling laser hangs from a control arm, still pointing down at him.
Riker has Malencon transported to the Enterprise-D sickbay, but indeed Crusher cannot save him. In the meantime, they have the power to the hydraulics room shut down. Kim, Mandl, Troi, and Riker head to the ship as well; the rest stay to survey the damage.
Data finds it interesting that the laser seemed to stop at the moment Malencon stopped screaming. He reactivates power to the room and reruns the drilling program. Data watches the beam run its cycle as it blasts down into each of the bore holes. He turns away for a moment to check the readouts. Suddenly, the beam pivots toward him. He quickly dodges the stream as it blasts past him. It fires again, but he is saved by his android reflexes. La Forge and Benson come to the rescue, but find the door is sealed again. Beyond it, they hear a horrendous crash and the smashing of equipment. La Forge screams Data’s name but receives no answer. They finally get the hatch open, and find that Data has ripped the machine down from its mounting. Data described what happened in the time he was trapped in the room, suggesting that the laser drill was being controlled by someone – or something – intelligent, as it appeared to be tracking his movements. The whole device lies mangled on the floor, and Bensen laments that a year’s work has been destroyed.
In Picard’s ready room, he tells Mandl he is shutting down operations until the matter is investigated; Mandl is outraged, stating that Picard is overstepping his authority. Picard says a member of his crew has been attacked, which gives him the right to intervene. Mandl reminds him that he has a delicate schedule to maintain, but Picard says it is on hold until he has answers. Yar escorts Mandl to his temporary quarters and now La Forge and Data inform him the drilling laser was somehow reprogrammed to kill anyone who entered the room. The three remaining terraformers seem to be the only possible suspects. Picard wonders what is so important that someone would want to kill for it. He instructs La Forge and Data to return to the planet to look for any sabotage or tampering. He also tells Yar to dig up the service records of all the terraformers for himself, and Counselor Troi to review and look for a possible motive.
Data and La Forge return to the station. Data notices a strange flicker of light down at the far end of one of the bore shafts. He makes sure it isn’t a reflection, then scans it with his tricorder. He gets no readings, so he asks La Forge to look at it with his VISOR. Using its various visual modes, La Forge scans the object. It’s inorganic, yet the pulses of light and color are unexplainable. Data wonders if it could be alive; it might be what the terraformers are trying to cover up… and the reason that Malencon is now dead.
The object is beamed to the Enterprise-D, where Dr. Crusher has it placed inside a glass bell jar for analysis in a medical lab. The computer makes scans and verifies that it contains no organic molecules. Crusher enhances the scan on the wall display, which shows a complex pattern of crystalline forms. Energy patterns flow throughout a beautiful network of structures. It begins to emanate an audible hum. Crusher asks the computer what is causing the flashes and noise, but it is uncertain, since it is theoretically impossible for the substance to produce such an effect. However, it gets louder as they approach the object. She asks the computer for a hypothesis, to which it replies: “Life“.
Picard relays the findings to Mandl and his staff. Mandl reiterates that the Federation verified Velara III to be lifeless, but Picard says this was an understandable mistake given the novel nature of the lifeform. Regardless, Picard mentions his suspicions that Mandl knew there was life down there; if so, he was in direct violation of the Prime Directive. Mandl makes it clear that he is in the business of creating life, not taking it. He leaves, and now Troi and Yar make it clear he suspected the truth but did not intend to commit murder. Furthermore, only he and Malencon would have necessary skills to program the drill in the manner it behaved. Terraformers have a tendency towards obsessiveness, which Yar thinks could be a motive for murder.
Riker asks about the designer, Luisa Kim. Troi says that she has a lot of vision, but isn’t driven by data, and she thinks that Riker might have a better chance of getting information out of her.
Riker goes to Luisa’s quarters, where she is looking out of the window with tears running down her face. She asks him if it’s true that they’ve found a lifeform. He says that it’s inconclusive because it’s inorganic. She’s upset because all the work she’s put into the project may have been for nothing.
Back in the medical lab, Crusher calls for Picard for new information. Picard arrives, and La Forge indicates he has detected a shift in the infrared spectrum; its internal structure is somehow changing. Suddenly, the small flicker of light brightens, nearly blinding everyone in the room. The hum grows louder as well. The hum and light subside, revealing two points of light inside the bell jar. Data points out that only life can replicate itself. As a precaution, Crusher activates a containment field around the bell jar, but the computer has trouble maintaining the field. The computer indicates that a “translation request” is being made; the glowing objects are trying to communicate with the computer. Power is increased to the containment field, but the fight for control continues. It looks as if Data is right; it’s a lifeform, and also intelligent, with the power to access the computer. Everyone evacuates the lab.
In the observation lounge, Picard now directly confronts Mandl, asking if he knew there was life on Velara III. He admits he knew of random energy patterns that disrupted their drilling, but that hardly indicated life by anything he is aware of. He adds they’re meaningless silicon crystals that rebroadcast sunlight. Picard tells him they are hardly meaningless; they are clearly alive and intelligent, and are trying to communicate.
Mendl was assured, before the team originally went to Velara III, that there was no life on the planet. They believed what the Federation scientists told them, so they didn’ think to look for themselves. Bensen then mentions light patterns in the sand, like sunlight bouncing off fresh snow. At first they thought it was just unique to the planet. But after a while they ceased to be random and a pattern could be identified. Picard asks if they ever felt that these patterns might be an attempt to communicate. Mandl says he didn’t, but Bensen wasn’t sure.
By now, the bell jar contains a cluster of several points of light. Data, La Forge and Worf further the analysis and confirm its structure and properties. From engineering, however, an ensign reports that the power fluctuations are increasing, causing numerous systems around the ship to go haywire; something is taking over. Soon, the universal translator comes online by itself, saying “Ugly giant bags of mostly water!” Picard is confused, and Data indicates it is an accurate description of Human physiology; he points out that Humans are 90% water surrounded by a flexible container.
The crystals speak, saying they had asked the Humans to leave, but they did not listen. It has driven them to kill. Picard tries to reassure the crystals that they come in peace; they didn’t understand the message, and were unaware there was life on the planet. The crystals object, stating the “bags” at the station knew. They tried peaceful contact, but were ignored, and some were killed. They have no choice now but to declare war. Before Picard can respond, the crystals end communication. At this point the whole ship is jarred by a force. Data indicates that the crystals have joined together into a kind of living computer he calls a “microbrain“; the more there are, the stronger they become.
Data identifies the flashes of light they emit appear to be program instructions allowing them to interface with the ship’s computers. Additionally, it is intelligent enough to interface faster than the crew can. After a quick flare up of energy and more disturbances in the ship, the crystals seem to power down. Crusher indicates that with single-celled organic life, replication follows a resting state; perhaps it is the same for the microbrain. Picard orders Yar to beam the entity back to the planet. She tries to energize the beam, but the beam is redirected. Picard is agitated; lifeform or not, the safety of the ship is at stake. He tells Data to remove the atmosphere from the medical lab. Data tries, but again, the controls are locked out.
Picard meets with the terraformers, explaining that the entity said it has tried to contact them before, but they ignored it. Mandl claims that if it tried communicating, they didn’t understand it; how were they to know? Picard wants to know what the terraformers did to cause the crystals to fight back. Kim indicates Malencon was siphoning off a layer of saline water on the surface of the sand. Crusher suggests that life needs water; perhaps it was sustaining them. Data suggests that as saline water conducts electricity, it might have been what linked them together; individually, a single brain cell is not intelligent, but when linked to others, intelligence is formidable. To prevent the loss of the saline, it drove them to kill.
The image of the medical lab shows the mass in the bell jar growing brighter. Suddenly, the glass shatters and now the crystal is large enough to see. Data and La Forge come up with an idea; they had detected cadmium salts, which create electrical current under infrared light. Perhaps the crystals are photoelectric in nature. Picard orders the lights in the medical lab killed, but again the controls do not work. Riker opens an access panel at the room, and disables the lighting that way. Now in total darkness, the glow of the microbrain begins to soften, and the crystals communicate, begging for more light. They reluctantly declare the war to be over if they are returned to the “wet sand”. Picard has Riker bring the lights back up, just a bit, to relieve them of their torment. He expresses his apologies for having caused them harm, and has the transporter chief beam the entity back to Velara III.
Afterward, Picard places an indefinite quarantine on the planet. Data is disappointed that they couldn’t learn more about the strange lifeform. They set course to the nearest starbase to drop off the surviving terraformers.