Sabotage fails but reveals Krotons' weakness

The crew assesses the aftermath of their sabotage attempt on the Krotons' Dynatrope, only to discover their efforts have failed to stop the crystalline beings. As tremors cease—signaling the Krotons' imminent freedom—the Doctor and Zoe tend to Thara's injured leg while Vana delivers a small sample of sulphuric acid, their last hope for destroying the power source. Selris reveals the sabotage failed, but the Doctor spots a leaking power sphere, exposing a critical vulnerability in the Krotons' energy system. The moment shifts urgency toward Jamie's disappearance, now trapped inside the Dynatrope, and the Doctor's realization that the acid must be mass-produced to exploit the Krotons' weakness before they escape. The scene pivots from failure to a desperate new plan, with the crew's survival hinging on Beta's ability to scale up the acid production.

Plot Beats

The narrative micro-steps within this event

2

Zoe attends to Thara's injured leg following the tremor while the Doctor urges them to move quickly, revealing that the source of the shaking has ceased, implying the Krotons will soon be free to act.

concern to urgency ['Under Hall']

Selris informs the Doctor that their attempt to sabotage the machine has failed, but the Doctor notes a sphere leaking fluid, suggesting the Krotons' power is compromised. He then asks about Beta's progress on making acid, and Vana delivers a small sample.

defeat to cautious hope ['Under Hall']

Who Was There

Characters present in this moment

8

Not directly observable, but inferred as fearful and disoriented—Jamie, a warrior accustomed to direct conflict, would be at a loss in the alien machinery, his survival instincts clashing with the Krotons’ logic. The crew’s concern for him humanizes the larger struggle.

Jamie’s absence is a critical subplot, revealed through Selris’ confirmation that he followed the Doctor into the Dynatrope. His untrained mind makes him potentially useless to the Krotons as a power source, but his captivity raises the stakes—both for his personal safety and as a potential distraction or leverage point. The crew’s realization that he’s trapped inside the machine forces them to act faster, blending rescue with sabotage.

Goals in this moment
  • To survive inside the Dynatrope until rescued
  • To avoid being absorbed or killed by the Krotons
Active beliefs
  • The Doctor and Zoe will find a way to get him out
  • His untrained mind might actually work in his favor (the Krotons won’t know what to do with him)
Character traits
Symbol of personal stakes in the mission Unintentionally pivotal (his capture changes the plan) Represents the crew’s emotional vulnerability Potential wild card in the Krotons’ machine
Follow Jamie McCrimmon's journey

Urgent and slightly repulsed (by the acid), but her concern for Jamie cuts through the clinical focus. She’s frustrated by the sabotage’s failure but sees the leaking sphere as a glimmer of hope—though Jamie’s disappearance adds a personal stake to the urgency.

Zoe takes on a dual role as medic and strategist, swiftly assessing Thara’s leg injury and improvising a splint using the Doctor’s pocket handkerchief. Her scientific mind immediately recognizes the sulphuric acid’s potential, though she’s repulsed by its corrosive properties. She voices concern for Jamie’s safety, revealing her emotional investment in the crew’s well-being even amid the crisis.

Goals in this moment
  • To stabilize Thara’s injury so he can rejoin the fight
  • To ensure the sulphuric acid is used effectively against the Dynatrope’s vulnerability
Active beliefs
  • The Krotons’ machine can be defeated through scientific exploitation of its weaknesses
  • Jamie’s untrained mind makes him vulnerable, but not necessarily useless in the broader plan
Character traits
Resourceful and adaptable Emotionally attuned to the crew Scientifically precise Quick to identify opportunities (and risks)
Follow Zoe Heriot's journey

Not applicable (as an organization), but their implied state is one of imminent triumph—until the Doctor spots the sphere’s leak, introducing a crack in their invulnerability. The Krotons’ confidence is their weakness: they assume no Gond or TARDIS crew member could exploit such a flaw.

The Krotons are an ever-present, looming threat, their machine’s unharmed state and impending freedom driving the crew’s desperation. Though not physically visible in this scene, their influence is palpable—through the leaking sphere (a sign of vulnerability) and the revelation that Jamie is trapped inside their stronghold. Their crystalline logic and ruthless efficiency contrast sharply with the Gonds’ improvisational defiance.

Goals in this moment
  • To escape the planet using the Dynatrope’s power
  • To eliminate all threats (including Jamie and the Doctor) to their mission
Active beliefs
  • Their technological superiority ensures victory over lesser beings
  • The Gonds and TARDIS crew are insignificant obstacles to be removed
Character traits
Omnipresent as an existential threat Symbol of cold, unfeeling domination Vulnerable only through exploitation of flaws (like the leaking sphere) Indirectly driving the crew’s urgency
Follow Lead Kroton's journey
Thara
primary

Physically pained but mentally sharp, oscillating between frustration at the failed sabotage and relief that the crew is tending to him—though his concern for the larger mission remains unspoken.

Thara lies injured in the Under Hall, his leg pinned and potentially fractured, as Vana cradles his head and Zoe assesses the damage. He grimaces in pain but remains conscious, his frustration palpable as the crew’s sabotage fails and the Krotons’ threat looms. Though physically compromised, his presence grounds the group’s urgency, symbolizing the personal cost of their struggle.

Goals in this moment
  • To recover quickly and rejoin the fight against the Krotons
  • To avoid becoming a liability to the crew’s efforts
Active beliefs
  • The Krotons’ defeat is essential for Gond survival, even if he can’t fight directly
  • His injury is a temporary setback, not a defeat
Character traits
Stoic under pain Frustrated by inaction Symbolic of Gond resilience Dependent on others’ care
Follow Thara's journey
Vana
primary

Concerned but composed, channeling her anxiety into practical support for Thara and the Doctor’s plan. Her focus on the acid delivery reflects her belief that action—no matter how small—can turn the tide.

Vana acts as the emotional and logistical anchor of the group, cradling Thara’s head to comfort him while assisting Zoe in stabilizing his leg. She delivers the small vial of sulphuric acid to the Doctor, updating him on Beta’s progress—a critical link in the chain of communication and action. Her calm demeanor belies the urgency of the moment, ensuring the crew remains coordinated despite the chaos.

Goals in this moment
  • To ensure Thara’s injury is managed so he doesn’t slow the group down
  • To facilitate the Doctor’s access to the sulphuric acid, knowing it’s their only remaining weapon
Active beliefs
  • The Gonds’ survival depends on unity and quick adaptation
  • Even small contributions (like the acid) can be decisive in the fight against the Krotons
Character traits
Nurturing and protective Efficient under pressure Bridge between Gond and TARDIS crew Quietly authoritative
Follow Vana's journey

Initially frustrated by the sabotage’s failure, but his discovery of the leaking sphere shifts him into a state of determined excitement. Jamie’s disappearance adds a layer of personal stakes, but the Doctor channels it into a clear next step: exploit the weakness. His emotional state is a mix of scientific thrill and protective urgency.

The Doctor shifts rapidly between roles—field medic, strategist, and leader—urging Zoe to hurry with Thara’s splint while his eyes lock onto the leaking power sphere, a critical flaw in the Dynatrope. His realization that Jamie is missing inside the machine sparks a renewed sense of purpose, blending concern for his companion with the scientific opportunity the sphere presents. He’s the catalyst for the group’s pivot from despair to action.

Goals in this moment
  • To exploit the Dynatrope’s leaking sphere with the sulphuric acid before the Krotons escape
  • To rescue Jamie, leveraging the machine’s vulnerability as a distraction or entry point
Active beliefs
  • The Krotons’ machine, though advanced, has exploitable flaws—especially when damaged
  • Jamie’s presence inside the Dynatrope, while dangerous, might create an unexpected opportunity
Character traits
Hyper-focused under pressure Blends scientific curiosity with emotional urgency Driven by pattern recognition (spotting the sphere’s leak) Quick to adapt plans when old ones fail
Follow The Second …'s journey
Supporting 2

Not directly observable, but inferred as determined and focused—his success with the acid is a quiet act of rebellion against Kroton oppression, and the crew’s reliance on him suggests a growing trust in Gond scientific capability.

Beta is mentioned indirectly through Vana’s delivery of the sulphuric acid, his role as the Gond chemist critical to the crew’s new strategy. Though absent from the scene, his work is the linchpin of their desperate gambit, symbolizing the Gonds’ scientific potential and defiance. The small vial he produced represents both his capability and the urgency of scaling up his efforts.

Goals in this moment
  • To produce enough sulphuric acid to exploit the Dynatrope’s weakness
  • To prove the Gonds’ scientific independence from Kroton control
Active beliefs
  • The Krotons’ machine can be defeated through Gond-made solutions
  • His work is a step toward freeing his people from alien domination
Character traits
Indirectly pivotal (his work drives the next phase) Symbol of Gond ingenuity Reliable under pressure (despite inexperience) Representative of the Gonds’ self-sufficiency
Follow Beta Dalek's journey

Defeated but not despairing, Selris carries the burden of failed leadership—yet his confirmation of Jamie’s disappearance refocuses the group’s energy. There’s a quiet relief that the Doctor has spotted a potential weakness, offering a path forward despite the odds.

Selris delivers the grim news of the sabotage’s failure, his voice heavy with the weight of Gond leadership. He confirms Jamie followed the Doctor into the Dynatrope, adding another layer of urgency to the crisis. Though physically present, his role is largely informational, grounding the group in the reality of their setback while deferring to the Doctor’s scientific leadership for the next move.

Goals in this moment
  • To ensure the crew remains united despite the sabotage’s failure
  • To support the Doctor’s new plan, even if it means relying on external (TARDIS) resources
Active beliefs
  • The Gonds’ survival depends on adapting to unexpected opportunities (like the leaking sphere)
  • The Doctor’s scientific mind is their best chance against the Krotons
Character traits
Resigned but not defeated Deferential to the Doctor’s expertise Bearer of bad news with quiet authority Symbol of Gond leadership’s limitations
Follow Selris's journey

Objects Involved

Significant items in this scene

5
Doctor's Handkerchief (Used to Block Gas Nozzle)

The Doctor’s pocket handkerchief, offered as an alternative to his braces for strapping Thara’s leg, becomes a symbol of improvisation and care. Its mundane origins contrast with its critical role in the moment, reflecting the crew’s ability to adapt with whatever tools are at hand. The handkerchief’s use underscores the personal stakes of the mission—even small, everyday objects can become pivotal in a life-or-death situation.

Before: Folded neatly in the Doctor’s pocket, an unremarkable …
After: Used to secure the wooden splint on Thara’s …
Before: Folded neatly in the Doctor’s pocket, an unremarkable personal item.
After: Used to secure the wooden splint on Thara’s leg, now slightly soiled but functionally essential.
Dynatrope Core Power Generation System

The Dynatrope looms as the antagonist device, its unharmed state after the sabotage attempt a crushing setback. However, the Doctor’s sharp eyes catch a leaking power sphere—a critical vulnerability in its energy system. This flaw transforms the machine from an invincible threat into a target, its crystalline components now susceptible to the sulphuric acid. The sphere’s leak symbolizes the Krotons’ overconfidence and the crew’s slim chance to turn the tide.

Before: Fully operational but damaged by the sabotage attempt, …
After: Identified as the key to the crew’s counterattack, …
Before: Fully operational but damaged by the sabotage attempt, with a previously undetected leak in one of its power spheres.
After: Identified as the key to the crew’s counterattack, with the leaking sphere becoming the focal point for their acid-based sabotage plan.
Gonds' Sulphuric Acid Sabotage Weapon

The small vial of sulphuric acid delivered by Vana is the crew’s last hope—a corrosive weapon against the Dynatrope’s crystalline structure. Though initially repellent to Zoe (who recoils at its smell), the Doctor recognizes its potential to exploit the leaking power sphere, turning a Gond-made solution into a critical tool. Its limited quantity underscores the urgency of Beta scaling up production, as this single vial is insufficient for a full-scale attack.

Before: Stored in Beta’s makeshift laboratory, freshly produced but …
After: Handed to the Doctor, now a focal point …
Before: Stored in Beta’s makeshift laboratory, freshly produced but untested in combat.
After: Handed to the Doctor, now a focal point for the crew’s desperate plan to sabotage the Dynatrope.
Krotons' Dynatrope Power Sphere

The leaking power sphere on the Dynatrope is the event’s narrative pivot—a glaring flaw in an otherwise invincible machine. The Doctor’s observation of its leak shifts the crew’s focus from despair to a desperate plan, as the sphere’s vulnerability becomes the key to exploiting the Krotons’ weakness. Its drip of fluid is both a warning (of the Krotons’ impending freedom) and an opportunity (for the acid sabotage), embodying the precarious balance of the moment.

Before: Sealed within the Dynatrope’s energy system, undamaged until …
After: Exposed and leaking, now a target for the …
Before: Sealed within the Dynatrope’s energy system, undamaged until the sabotage attempt.
After: Exposed and leaking, now a target for the sulphuric acid and the crew’s last hope.
Thara's Wooden Leg Splint

The wooden leg splint, improvised from debris in the Under Hall, serves as a temporary medical solution for Thara’s fractured leg. Though crude, it stabilizes him enough to rejoin the fight, symbolizing the crew’s resourcefulness in the face of crisis. Zoe directs its use, strapping it tightly with the Doctor’s pocket handkerchief—a practical but emotionally charged moment that highlights their unity under pressure.

Before: A rough piece of wood lying amid the …
After: Attached to Thara’s leg, providing enough support for …
Before: A rough piece of wood lying amid the rubble of the Under Hall, unnoticed until needed.
After: Attached to Thara’s leg, providing enough support for him to move (though not without pain).

Location Details

Places and their significance in this event

1
Under Hall

The Under Hall serves as a fragile refuge and tactical meeting point, its dust-choked air and collapsing walls mirroring the crew’s desperation. The space is both a sanctuary (where Thara’s injury is tended) and a pressure cooker (where the failure of the sabotage is revealed). Its instability—debris crashing from the ceiling, vibrations from the Dynatrope—creates a sense of urgency, reinforcing the crew’s need to act quickly before the Krotons strike.

Atmosphere Tension-filled with whispered conversations and the looming threat of collapse, both physical (from the unstable …
Function Tactical meeting point and makeshift medical bay, where the crew assesses their failure, tends to …
Symbolism Represents the Gonds’ resilience amid oppression—a space of both vulnerability and defiance, where even in …
Access Open to the crew and Gonds, but heavily damaged and structurally unstable. The Krotons’ machine …
Dust hangs thick in the air, obscuring vision and coating surfaces. Debris from the ceiling crashes intermittently, heightening the sense of urgency. The leaking power sphere from the Dynatrope casts an eerie glow, drawing the crew’s attention. The space is dimly lit, with shadows emphasizing the crew’s isolation and desperation.

Organizations Involved

Institutional presence and influence

2
Krotons

The Krotons are an ever-present, looming force, their machine’s unharmed state and impending freedom driving the crew’s desperation. Though not physically visible, their influence is felt through the leaking sphere (a sign of vulnerability) and the revelation that Jamie is trapped inside their stronghold. The organization’s cold, crystalline logic contrasts with the Gonds’ improvisational defiance, their overconfidence in their technology creating the opportunity for exploitation. The Krotons’ power dynamics are one of dominance, but the Doctor’s discovery of the sphere introduces a crack in their invulnerability.

Representation Through the Dynatrope’s unharmed state and the leaking power sphere, which symbolizes their technological superiority—and …
Power Dynamics Exercising authority over the Gonds and TARDIS crew, but facing an unexpected challenge from the …
Impact The Krotons’ institutional impact is one of oppression, but the crew’s discovery of the leaking …
Internal Dynamics The Krotons operate as a hive mind, with no internal dissent or hierarchy—until the moment …
To escape the planet using the Dynatrope’s power, eliminating all threats in the process. To absorb Jamie’s mind as a potential (though untrained) power source. Through the Dynatrope’s machinery, which drains mental energy and enforces control Via the threat of lethal gas and vaporization (as seen in Selris’ earlier warnings) By manipulating the Gonds’ fear and dependency on their technology
Gond Indigenous Population

The Gond Society is represented through Selris’ leadership, Vana’s logistical support, and the collective urgency to exploit the Dynatrope’s weakness. Their organization is on the brink of collapse after the sabotage failure, but the Doctor’s discovery of the leaking sphere reignites their hope. The Gonds’ scientific potential (embodied by Beta’s acid) becomes their best chance to reclaim agency, shifting from passive resistance to active defiance. The crew’s unity—Gonds and TARDIS companions alike—symbolizes the organization’s resilience.

Representation Through collective action (Selris’ updates, Vana’s delivery of the acid, the crew’s improvised medical care) …
Power Dynamics Operating under constraint (the Krotons’ dominance) but seizing an unexpected opportunity (the leaking sphere) to …
Impact This moment marks a shift from Gond passivity to proactive resistance, with the crew’s actions …
Internal Dynamics Tensions between caution (Selris’ initial defeatism) and bold action (the Doctor’s pivot to the leaking …
To destroy the Dynatrope before the Krotons escape, using the sulphuric acid as a weapon. To prove the Gonds’ scientific capability and independence from Kroton control. Through Beta’s acid production (a Gond-made solution to a Gond problem) Via Selris’ leadership in coordinating the crew’s efforts By leveraging the Doctor’s expertise to exploit the Dynatrope’s vulnerability

Narrative Connections

How this event relates to others in the story

What led here 2

"Vana explains that she and Thara remained to prepare sulphuric acid for the Doctor. Later, Vana delivers a small sample to the Doctor."

Vana reveals the acid plan
S6E22 · The Krotons Part 4
Causal medium

"Zoe cares for Thara and the Doctor urges them to move. The Doctor notes a fluid leak and asks about Beta's progress on the acid before Vana delivers a sample, which all occur sequentially."

Jamie’s disappearance escalates the crisis
S6E22 · The Krotons Part 4
What this causes 3

"The Doctor asks about Beta's progress on making acid (beat_7bdc8524865d6dd9), then tasks Jamie with getting Beta to mass-produce sulphuric acid (beat_59a1972cb980fc2a)."

Jamie rescued and dispatched on mission
S6E22 · The Krotons Part 4
Causal medium

"Zoe cares for Thara and the Doctor urges them to move. The Doctor notes a fluid leak and asks about Beta's progress on the acid before Vana delivers a sample, which all occur sequentially."

Jamie’s disappearance escalates the crisis
S6E22 · The Krotons Part 4

"Zoe reminds the Doctor about Jamie, whom the Doctor had forgotten, because Jamie went into the Dynatrope earlier. Later, Jamie is found attempting to escape the Dynatrope."

Jamie discovers the Doctor’s mica clue
S6E22 · The Krotons Part 4

Themes This Exemplifies

Thematic resonance and meaning

Key Dialogue

"SELRIS: Yes Doctor, I'm afraid we have failed. The machine is unharmed."
"DOCTOR: I'm not so sure - look at that. [pointing to leaking sphere] I'd say it was no longer functioning under full power."
"ZOE: Doctor, what about Jamie?"
"DOCTOR: Jamie! I'd forgotten all about him in the excitement!"
"VANA: Doctor! [handing over acid sample] He only made a small amount to start with."