Fabula
Season 7 · Episode 19
S7E19
Tragic with fleeting hope
Written by Brannon Braga
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Genesis

When a synthetic T-cell used to cure Barclay's illness mutates and becomes airborne, it causes the Enterprise crew to de-evolve into earlier forms of life, forcing Picard and Data to race against time to find a cure before they all transform completely.

The USS Enterprise encounters a bizarre crisis when a synthetic T-cell, initially administered to cure Lieutenant Barclay of a minor illness, unexpectedly mutates and spreads throughout the ship. This modified T-cell activates dormant introns within the crew's DNA, triggering a rapid de-evolution into earlier forms of life.

The crisis begins subtly with crew members experiencing strange symptoms: Riker's slowed thinking, Troi's increased sensitivity to temperature, and Worf's aggressive behavior. Beverly Crusher discovers the source of the problem when she finds a venomous sac developing on Worf's neck, leading to a shocking attack that leaves her incapacitated. As the situation worsens, the crew physically transforms, exhibiting traits of their evolutionary ancestors. Barclay rapidly gains energy and enhanced skills, while others show signs of regression.

Picard and Data, returning from a mission to recover a stray torpedo, find the Enterprise adrift and in chaos. The crew has scattered, with many devolving into animalistic states. They discover Troi in her quarters, transformed into an amphibian, and encounter Riker devolved into a proto-human. Data determines that the crew is de-evolving due to activated introns, remnants of genetic code from earlier stages of evolution.

As Picard begins to experience his own de-evolution, becoming more fearful and instinct-driven, he and Data race against time to find a solution. They discover that Nurse Ogawa, who is pregnant, carries an unaffected embryo. Data theorizes that the amniotic fluid could provide a template for a retro-virus to counteract the synthetic T-cell. The pair work to repair the ship's damaged systems and synthesize the retro-virus.

Their efforts are complicated when Worf, devolved into a primitive Klingon, fixates on Troi as his mate and relentlessly pursues her. Picard is forced to lure Worf away from Sickbay, using a pheromone-based distraction synthesized by Data from Troi's DNA. This leads to a harrowing chase through the ship's Jefferies Tubes, where Picard eventually subdues Worf using a plasma discharge.

Data successfully synthesizes and releases the retro-virus into the ship's atmosphere. Over time, the crew returns to normal. Beverly identifies the anomaly in Barclay's genetic chemistry as the catalyst for the crisis. The episode concludes with the crew recovering and Beverly considering naming the new ailment "Barclay's Proto-morphosis Syndrome."


Events in This Episode

The narrative beats that drive the story

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Act 1

The narrative opens in Sickbay, establishing Lieutenant Barclay's pervasive hypochondria, which Doctor Crusher addresses by administering a synthetic T-cell to combat a mild Urodelan Flu. During this initial sequence, Nurse Ogawa reveals her pregnancy, a detail that will prove critically important later, and Data entrusts Barclay with the care of his expectant cat, Spot. This seemingly innocuous setup subtly introduces the key biological elements and characters central to the unfolding crisis. Following this, Captain Picard and Data depart the Enterprise on a mission to retrieve a stray photon torpedo, leaving Commander Riker in temporary command. Almost immediately, during routine weapon tests, Lieutenant Worf exhibits unusual agitation and aggression, snapping at Riker and later displaying increasingly feral eating habits in Ten Forward, coupled with a disturbing, predatory gaze directed at Counselor Troi. Troi, in turn, begins to experience an uncharacteristic and intense sensitivity to cold. Worf's behavioral regression escalates further as he instinctively constructs a crude nest in his quarters, adopting a fetal sleeping position, signaling a profound, primordial shift within his biology. These early, unsettling changes among key crew members serve as the initial tremors of the widespread de-evolution about to engulf the ship, effectively establishing the central mystery and strategically removing the two most capable problem-solvers from the immediate scene. The synthetic T-cell, administered to Barclay, stands as the silent, unseen catalyst for the impending biological catastrophe.

Act 2

The de-evolutionary symptoms among the crew intensify and spread rapidly. Lieutenant Barclay displays extreme hyper-energy, rapid speech, and nervous tics, indicating an accelerated metabolic state, while Commander Riker's cognitive abilities noticeably decline, rendering him slow and struggling to comprehend technical reports or diagrams. In Engineering, Barclay and Geordi discover a corroded panel, suggesting an unknown, highly corrosive organic solvent is at work, a precursor to the biological nature of the threat. Simultaneously, Counselor Troi's obsession with warmth and hydration escalates dramatically, leading her to immerse herself in her bathtub, fully clothed, in a desperate, instinctual attempt to regulate her rapidly changing body temperature. On the Bridge, Riker's mental incapacitation becomes profound, rendering him unable to make even basic decisions or recall recent events, leaving the ship's command structure critically compromised. The crisis culminates dramatically when Worf, now fully consumed by primal instincts, violently bites Troi on the cheek. Doctor Crusher, investigating Worf's increasingly erratic and animalistic behavior, discovers a strange, veiny venomous sac developing on his neck. Before she can fully understand its implications, Worf attacks her with a blast of bio-acidic venom and escapes Sickbay, leaving her incapacitated and the medical bay in disarray. Nurse Ogawa reports widespread strange behavioral changes among sixty crewmen, confirming a rapidly spreading, unknown disease. The act concludes with Riker completely disoriented, staring vacantly out a window, unable to contact Starfleet, signifying the Enterprise's descent into chaos and the crew's complete loss of control.

Act 3

Captain Picard and Data return to the Enterprise after their three-day mission, finding the starship adrift, dark, and tumbling aimlessly through empty space. All internal systems are in emergency mode, and communication attempts fail entirely. Upon boarding the shuttlebay, they encounter a ship transformed into a primal, disorienting environment, filled with strange animalistic howls, screeches, and clicks, along with an abundance of pungent pheromones. Their initial exploration leads them to discover a long, dried reptilian skin husk, resembling a shed human-like epidermal layer, providing the first concrete evidence of profound biological changes. Their search for the crew leads them to Counselor Troi's quarters, now a steamy, humid, greenhouse-like environment. There, they find Troi submerged face-down in her bathtub, having de-evolved into an amphibian with prominent gill slits, oily skin, and inhuman golden eyes with vertical red slits. She gasps for air and shows no recognition of Picard or Data. Data's scans confirm her DNA is undergoing rapid re-sequencing, fundamentally altering her into an ancient, water-dwelling lifeform. They then find Ensign Dern dead on the Bridge, his body bearing severe scratch marks and a broken spinal column, consistent with an animal attack, and his DNA showing early stages of mutation. In the Ready Room, they encounter Commander Riker, who has devolved into a proto-human, exhibiting a pronounced forehead, large canines, and dark hair, attacking them with primal, unthinking aggression. Data definitively concludes that the entire crew is de-evolving, each transforming into earlier forms of life from their respective homeworlds. This act marks the grim realization of the catastrophe's true nature and terrifying scale, setting the stage for the desperate search for a cure.

Act 4

In Sickbay, Picard and Data examine the unconscious proto-human Riker. Data provides a detailed explanation of the de-evolutionary process: a synthetic T-cell has invaded the crew's genetic code, activating latent introns—dormant genetic codes from earlier evolutionary stages—which are now re-sequencing their DNA into ancestral configurations. Picard receives the alarming news that he, too, is infected and will begin his own de-evolution within twelve hours, likely into an early primate like a lemur. Seeking a solution, they move to Data's quarters, where they discover Spot has transformed into an iguana, but her newly born kittens are miraculously unaffected by the virus. This critical observation leads Picard to theorize that natural immune systems within the womb, specifically amniotic fluid, might contain antibodies capable of inhibiting the virus. Data identifies pregnant Nurse Ogawa as a potential human source for a retro-virus. Their efforts are interrupted by a ship-wide tremor, indicating a warp plasma vent failure, necessitating a trip to Engineering. In Engineering, Picard encounters Lieutenant Barclay, now a terrifying spider-like creature with bulbous black eyes and hooked hands, who attacks him. Picard experiences an intense, primal feeling of fear and panic, confirming his own impending transformation and the activation of his own ancestral instincts. They locate Ogawa, who is also beginning to de-evolve, and Data begins the urgent work of synthesizing a retro-virus from her unaffected embryo's amniotic fluid. The act culminates with Worf, now a heavily armored, monstrous Klingon, violently attacking the Sickbay door, trapping them and raising the stakes to an immediate, physical threat, as their time to find a cure rapidly diminishes.

Act 5

The climax unfolds with Worf, now a formidable, de-evolved Klingon, relentlessly attempting to breach the Sickbay door, trapping Picard and Data inside. Picard, battling his own escalating primal fears and instincts, deduces Worf's motivation: a powerful mating drive towards the amphibian Troi. Data swiftly synthesizes a highly amplified pheromone lure using Troi's genetic material. Picard, despite his terror and the onset of his own de-evolutionary symptoms, bravely takes the hypospray and ventures into the corridors to draw Worf away from Sickbay, allowing Data to continue working on the retro-virus. The chase is intense and harrowing, with Picard spraying pheromones to confuse Worf, who is revealed in his full, terrifying prehistoric Klingon form—a hulking creature with enormous, chitinous ridges, snapping mandibles, and immense strength. Trapped in a turbolift, Picard narrowly escapes into a Jefferies Tube. Worf pursues, spraying Picard with corrosive venom, causing painful acid burns on his arm. Cornered, Picard ingeniously uses the previously re-routed plasma cable from Act Two to electrocute Worf, subduing the creature without killing him. With Worf incapacitated, Data successfully synthesizes and releases the retro-virus into the ship's atmosphere. Over time, the crew gradually returns to their normal states. Doctor Crusher later explains the anomaly in Barclay's genetic chemistry caused the synthetic T-cell to mutate and activate dormant introns, leading to the widespread de-evolution. She proposes naming the new ailment “Barclay's Proto-morphosis Syndrome,” concluding the bizarre and dangerous ordeal with a touch of characteristic Starfleet humor.