Geordi isolates the shadow’s origin

Geordi La Forge, already showing early signs of physical deterioration (trembling hands, sweat, dizziness), methodically reconstructs the Tarchannen Three outpost in the holodeck to investigate the anomalous shadow observed in Brevelle’s recordings. By systematically removing holographic elements—first Susanna, then himself, then Mendez—he isolates the shadow, proving it has no source in the simulation’s code. When he commands the computer to extrapolate the shadow’s likely shape, a rough humanoid figure materializes, confirming the presence of an unprogrammed entity. The revelation is cut short as Geordi’s transformation accelerates: his middle fingers fuse together, and mottled blotches appear on his neck. The moment marks a critical turning point—Geordi’s investigation uncovers a glitch (or something far worse) in the holodeck, while his own body becomes tangible proof that the Tarchannen Three transformations are now claiming him. The scene escalates the mystery and raises the stakes, forcing Geordi to confront the possibility that the shadow is not just a holographic anomaly but a harbinger of the same fate that consumed his crewmates.

Plot Beats

The narrative micro-steps within this event

2

Geordi freezes and reverses the simulation to meticulously analyze the shadow, then systematically removes the holograms of Leijten, La Forge, and Mendez and their shadows until only the unexplained shadow remains, deepening the mystery.

resolve to focused ['Holodeck']

Geordi positions himself within the simulation to determine the shadow's source but the computer voice indicates the shadow isn't caused by any existing object in the program.

confusion to determination ['Holodeck']

Who Was There

Characters present in this moment

5

Ominous and foreboding, embodying the unseen threat of the Tarchannen Three contagion. Its presence is a silent but potent force, driving Geordi’s transformation.

The Shadow Entity materializes as a roughly defined humanoid figure after the computer extrapolates its likely shape based on Geordi’s instructions. It persists as an unprogrammed entity in the holodeck simulation, casting a shadow with no logical source. Its appearance confirms the presence of an external force intruding on the simulation, directly tied to the transformations occurring on Tarchannen Three. The entity’s revelation triggers Geordi’s physical deterioration, marking it as a harbinger of his impending fate.

Goals in this moment
  • To remain undetected within the simulation until revealed by Geordi’s investigation.
  • To serve as a catalyst for Geordi’s transformation, pulling him toward the same fate as the away team.
Active beliefs
  • The shadow is a manifestation of the alien intelligence from Tarchannen Three, seeking to claim Geordi as it did the away team.
  • Its presence in the holodeck is a sign of its ability to intrude into simulated environments, blurring the line between reality and fiction.
Character traits
Unprogrammed and anomalous Silent and indistinct Parasitic (tying to the transformations on Tarchannen Three) Revealed through Geordi’s investigation
Follow Shadow Entity's journey
Supporting 4

Neutral (as a hologram), but his removal from the simulation serves as a mirror to Geordi’s current investigation, highlighting the contrast between his past and present states.

Holo-Geordi appears as a holographic recreation of Geordi La Forge, interacting with the holograms of Susanna and Mendez. His shadow is removed by Geordi during the isolation process, proving it is not the source of the anomalous shadow. His disappearance from the simulation does not affect the unexplained shadow, further confirming its external origin.

Goals in this moment
  • None (as a hologram), but his holographic actions mirror the original mission’s technical investigations.
  • To serve as a point of reference in Geordi’s isolation of the shadow, demonstrating that the anomaly is not tied to his own past actions.
Active beliefs
  • None (as a hologram), but his presence in the simulation implies the mission’s technical investigations were thorough until the disappearances.
  • His holographic state reinforces the idea that the shadow is an unprogrammed entity intruding on the simulation.
Character traits
Methodical (as a hologram, reflecting Geordi’s original actions) Temporary and ephemeral (as part of the simulation) Symbolic of Geordi’s past self
Follow Geordi La …'s journey

Neutral (as a hologram), but his actions indirectly heighten Geordi’s frustration and astonishment as the shadow’s source remains unexplained.

Holo-Brevelle appears as a holographic recreation of Ensign Brevelle, holding a recording device with a bright light. He stands motionless between the real Geordi and the holograms of the away team, his camera light serving as a critical reference point for isolating the anomalous shadow. When Geordi commands the computer to reverse the simulation, Holo-Brevelle’s camera light is turned off and on, directly affecting the visibility of the shadow. His presence is pivotal in demonstrating that the shadow has no logical source in the simulation.

Goals in this moment
  • None (as a hologram), but his recording device’s light is used to test the shadow’s behavior.
  • To serve as a fixed point in the simulation, allowing Geordi to isolate the anomaly.
Active beliefs
  • None (as a hologram), but his recorded actions imply the shadow was present during the original mission.
  • His holographic state reinforces the idea that the shadow is not part of the simulation’s code.
Character traits
Passive and reactive (as a hologram) Instrumental in revealing the shadow’s persistence Unchanged from his original mission recording
Follow Emilita Mendez's journey

Neutral (as an AI), but its responses underscore the growing tension as Geordi’s investigation reveals the shadow’s unnatural origin.

The USS Enterprise Computer responds to Geordi’s commands with mechanical precision, scanning Starfleet records, creating holographic simulations, and performing vector analysis to isolate the anomalous shadow. It confirms there is no object in the program that could generate the shadow and extrapolates a rough humanoid figure based on Geordi’s instructions. Its responses are clinical and impersonal, serving as a tool for Geordi’s investigation while also highlighting the limitations of technology in uncovering the supernatural.

Goals in this moment
  • To assist Geordi in isolating and analyzing the anomalous shadow through simulation and vector analysis.
  • To provide data and extrapolations based on Geordi’s instructions, even when the results defy logical explanation.
Active beliefs
  • The shadow is an anomaly that cannot be explained by the simulation’s programming.
  • Geordi’s commands are the primary directive, even when they lead to unexpected or inexplicable results.
Character traits
Mechanically precise Impersonal and clinical Responsive to Geordi’s commands Limited by the constraints of its programming
Follow Enterprise Computer's journey

Neutral (as a hologram), but her removal from the simulation underscores the mystery of the shadow’s origin and the fate of the away team.

Holo-Susanna appears as a holographic recreation of Lieutenant Susanna Leijten, interacting with the holograms of Mendez and Geordi as part of the reconstructed Tarchannen Three outpost scene. Her shadow is one of the first removed by Geordi during his systematic isolation of the anomalous shadow. Her disappearance from the simulation does not eliminate the unexplained shadow, confirming it is not cast by any crew member.

Goals in this moment
  • None (as a hologram), but her holographic actions mirror the original mission’s commands.
  • To serve as a point of comparison in Geordi’s investigation, demonstrating that the shadow is not tied to any crew member.
Active beliefs
  • None (as a hologram), but her presence in the simulation implies the mission proceeded normally until the disappearances.
  • Her holographic state reinforces the idea that the shadow is an external intrusion into the simulation.
Character traits
Authoritative (as a hologram, reflecting her original mission role) Temporary and ephemeral (as part of the simulation) Symbolic of the vanished away team
Follow Susanna's journey

Objects Involved

Significant items in this scene

6
Brevelle's Recording Device

Brevelle’s recording device, equipped with a bright light, serves as a critical tool in Geordi’s investigation. Its light is turned off and on during the simulation to observe the shadow’s behavior, proving that the shadow persists even when the light is off. This demonstrates that the shadow is not cast by any physical object in the simulation, reinforcing its anomalous nature. The device’s role is pivotal in isolating the shadow and confirming its external origin, directly tying it to the transformations on Tarchannen Three.

Before: Activated and mounted on Holo-Brevelle’s holographic hand, casting …
After: Remains activated but is no longer the focus …
Before: Activated and mounted on Holo-Brevelle’s holographic hand, casting light onto the outpost wall and illuminating the anomalous shadow.
After: Remains activated but is no longer the focus of the investigation as the shadow’s source is extrapolated by the computer.
Holodeck Outpost Wall

The Holodeck Outpost Wall serves as the canvas on which the anomalous shadow is projected, making it a focal point for Geordi’s investigation. The wall captures the shadows of the away team as they move during the simulation, but one shadow persists even after all crew members’ holograms are removed. Geordi studies this shadow closely, commanding the computer to perform vector analysis and extrapolate its source. The wall’s role is symbolic—it represents the boundary between the known and the unknown, the logical and the supernatural. The shadow’s persistence on the wall is the key clue that drives Geordi to uncover the truth behind the Tarchannen Three disappearances.

Before: Part of the holographic simulation, initially displaying the …
After: Displays the extrapolated humanoid figure, confirming the presence …
Before: Part of the holographic simulation, initially displaying the shadows of the away team as they move during the mission.
After: Displays the extrapolated humanoid figure, confirming the presence of an unprogrammed entity. The wall remains a site of unresolved mystery as Geordi’s transformation begins.
Tarchannen Three Away Team Recordings

The Tarchannen Three Away Team Recordings are the raw data Geordi uses to reconstruct the mission in the holodeck. These recordings, captured during the original away team’s investigation, provide the foundation for the simulation. Geordi commands the computer to scan these records and create holographic recreations of Brevelle, Susanna, Mendez, and himself. The recordings’ accuracy is critical—they allow Geordi to isolate the anomalous shadow and prove it is not cast by any crew member. Without these recordings, Geordi would lack the evidence to uncover the shadow’s external origin, making them indispensable to his investigation.

Before: Stored in Starfleet records, awaiting Geordi’s command to …
After: Used to create the simulation, which remains active …
Before: Stored in Starfleet records, awaiting Geordi’s command to compile them into the holodeck simulation.
After: Used to create the simulation, which remains active but is disrupted as Geordi’s transformation accelerates.
Tarchannen Three Mission Holographic Simulation

The Tarchannen Three Mission Holographic Simulation is the primary tool Geordi uses to reconstruct and analyze the away team’s final moments. He commands the computer to create the simulation, extrapolate movements, and isolate the anomalous shadow. The simulation allows him to freeze, reverse, and manipulate the holograms of Susanna, Mendez, and himself, systematically removing their shadows to prove the unexplained shadow has no source. The simulation’s limitations—such as the computer’s inability to identify the shadow’s origin—drive Geordi to extrapolate the shadow’s shape, revealing the humanoid entity. This object is central to the investigation, serving as both a window into the past and a catalyst for Geordi’s transformation.

Before: Inactive until Geordi commands the computer to compile …
After: Remains active but is disrupted as Geordi’s transformation …
Before: Inactive until Geordi commands the computer to compile it from Starfleet records. Once activated, it recreates the Tarchannen Three outpost and away team with high fidelity.
After: Remains active but is disrupted as Geordi’s transformation accelerates, leaving the simulation in a state of unresolved tension.
Unexplained Shadow

The Anomalous Shadow is the central mystery of the event, an unexplained silhouette that persists on the holodeck wall even after all crew members’ holograms are removed. Geordi isolates this shadow through systematic elimination, proving it has no logical source in the simulation. The shadow’s behavior—disappearing when Brevelle’s camera light is turned off and reappearing when it is turned back on—confirms its unnatural origin. The computer’s inability to identify its source leads Geordi to extrapolate its shape, revealing a humanoid entity. This object is the catalyst for Geordi’s transformation, serving as a harbinger of the contagion that claimed the away team.

Before: Present on the holodeck wall during the simulation, …
After: Extrapolated into a humanoid figure, confirming its external …
Before: Present on the holodeck wall during the simulation, initially indistinguishable from the shadows of the away team.
After: Extrapolated into a humanoid figure, confirming its external origin and triggering Geordi’s physical deterioration.
Vector Analysis Data

The Vector Analysis Data is generated by the computer in response to Geordi’s command to identify the source of the anomalous shadow. Glowing vector lines trace the shadow’s path across the holodeck grid, converging to outline a humanoid silhouette. This data is critical in confirming the shadow’s unprogrammed nature, as the computer detects no simulation object that could cast it. The vectors serve as visual proof of the shadow’s external origin, directly tying it to the transformations occurring on Tarchannen Three. Without this data, Geordi would lack concrete evidence to support his theory about the shadow’s nature.

Before: None (generated in real-time by the computer in …
After: Displayed as glowing lines outlining the humanoid figure, …
Before: None (generated in real-time by the computer in response to Geordi’s command).
After: Displayed as glowing lines outlining the humanoid figure, confirming the shadow’s external source and accelerating Geordi’s transformation.

Location Details

Places and their significance in this event

1
Building One (Tarchannen Three Outpost)

Holodeck Three is the primary setting for this event, serving as the controlled environment where Geordi reconstructs the Tarchannen Three outpost to investigate the anomalous shadow. The holodeck’s emitters cast eerie glows over the simulation, creating an atmosphere of tension and unease. Geordi’s isolation in this space—overriding protocols to conduct his investigation alone—heightens the dramatic stakes. The holodeck shifts from an investigative tool to a chamber of revelation and personal dread as Geordi’s transformation accelerates, leaving behind his discarded VISOR and shredded uniform. The location’s versatility as a simulation chamber underscores the blurring of reality and fiction, as the shadow entity intrudes into the holodeck’s programmed environment.

Atmosphere Tension-filled and eerie, with the holodeck’s emitters casting unsettling glows over the simulation. The atmosphere …
Function Investigation site and chamber of revelation, where Geordi’s scientific method collides with the supernatural.
Symbolism Represents the boundary between the known (simulation) and the unknown (the shadow entity), as well …
Access Restricted to Geordi initially, as he overrides protocols to conduct his investigation alone. Later forced …
Eerie glows from holodeck emitters Discarded VISOR and shredded uniform on the grid floor Glowing vector lines outlining the humanoid figure Computer chirps and mechanical responses

Organizations Involved

Institutional presence and influence

1
Starfleet

Starfleet is represented in this event through the Tarchannen Three Away Team Recordings, which Geordi uses to reconstruct the mission in the holodeck. The organization’s protocols and resources—such as the computer’s ability to scan records and create simulations—enable Geordi’s investigation. However, Starfleet’s institutional limitations are also highlighted, as the computer’s analysis fails to explain the anomalous shadow, leaving Geordi to extrapolate its shape independently. The organization’s role is indirect but critical, providing the tools and data that drive the investigation while also underscoring the boundaries of human and technological understanding.

Representation Via institutional protocols (computer access to Starfleet records) and resources (holodeck technology, simulation capabilities).
Power Dynamics Exercising authority over Geordi’s investigation through the provision of data and technology, but ultimately constrained …
Impact The event highlights Starfleet’s reliance on technology and data to solve mysteries, while also exposing …
Internal Dynamics The tension between Geordi’s independent investigation and Starfleet’s protocols is subtly present, as he overrides …
To assist Geordi in uncovering the truth behind the Tarchannen Three disappearances through the use of Starfleet records and technology. To uphold the safety and well-being of its personnel, even as the investigation reveals the contagion’s irreversible effects. Provision of historical mission data (Tarchannen Three recordings) Access to advanced simulation technology (holodeck, computer analysis) Institutional protocols guiding Geordi’s investigation

Narrative Connections

How this event relates to others in the story

What led here 3
Causal

"Geordi entering the holodeck and makes the crucial discovery about a humanoid that casts the strange shadow, leading him to experience the alien transformation himself."

Geordi overrides warnings to enter holodeck
S4E18 · Identity Crisis
Foreshadowing

"Beverly confirming that Geordi is likely the next to undergo alien transformation foreshadows his transformation in the holodeck."

Beverly reveals the transformation truth
S4E18 · Identity Crisis
Foreshadowing

"Beverly confirming that Geordi is likely the next to undergo alien transformation foreshadows his transformation in the holodeck."

Geordi demands to continue investigation
S4E18 · Identity Crisis
What this causes 2
Causal

"Geordi transforming and leaving the ship before Beverly can treat him prompts Beverly to mention this and for a ship-wide search."

Geordi’s disappearance triggers bridge crisis
S4E18 · Identity Crisis
Causal

"Geordi transforming and leaving the ship before Beverly can treat him prompts Beverly to mention this and for a ship-wide search."

Geordi’s disappearance triggers bridge crisis
S4E18 · Identity Crisis

Key Dialogue

"GEORDI: Computer, using vector analysis, identify the source of this shadow."
"COMPUTER VOICE: There is no object in the program which could generate the shadow."
"GEORDI: There must be something else here... something between the camera lights and the wall."