Doctor Who
S20E6
· Snakedance Part 2

Doctor and Nyssa discover Mara's conduit through Tegan

With the experiment complete the Doctor and Nyssa watch the fading blue light from the crystal: small in size, infinite in implication. The Doctor immediately reframes their observation from wonder to utility, deducing that thought can be converted into raw energy, even matter itself. Nyssa makes the leap that the same principle could enable the Mara’s parasitic consciousness to seize physical form again, hefting Tegan’s pliable psyche as the vessel. Realizing time has run out and Ambril’s own authority governs the Great Crystal’s location, the Doctor resolves to beg one final audience, gambling every hope on reluctant bureaucracy.

Plot Beats

The narrative micro-steps within this event

2

The Doctor and Nyssa analyze the results of their experiment with the small crystal, understanding its power to transform thought into energy.

curiosity to determination ['TARDIS']

The Doctor explains the implications of the Mara's connection to Tegan's mind and the Great Crystal, revealing their plan to manifest physically.

clarity to urgency

Who Was There

Characters present in this moment

2
The Fifth Doctor
Time Lord
 primary

Driven urgency masking a latent dread—the ticking clock of a doomsday barely avertable

The Doctor stands at the TARDIS console, cradling the Great Crystal which pulses faintly with residual blue light. He transforms awe into action, theorizing the crystal’s transformative potential aloud and pivoting from observation to urgency with precise, rapid-fire logic. His physical posture radiates restless purpose as he grasps the artifact and prepares to leave.

Goals in this moment
  • • Convince Nyssa of the crystal’s deadly function and the urgency of acting on it.
  • • Reach Ambril before the Mara can consolidate its physical manifestation through Tegan.
Active beliefs
  • • The Great Crystal’s energy conversion principles can be weaponized for either salvation or annihilation.
  • • Bureaucratic inertia can still be overcome by rational persuasion and moral clarity.
Character traits
theoretical clarity under pressure rapid conceptual leaps authoritative rhetoric experimental improvisation urgent decisiveness
Follow The Fifth …'s journey
Nyssa
Companion of the Doctor
 primary

Intense intellectual focus punctured by creeping dread at the implications for Tegan

Nyssa leans against the console, eyes fixed on the crystal’s fading glow. She absorbs the Doctor’s deduction and immediately pivots to the Mara’s implication, her analytical mind anticipating catastrophe. With quiet intensity, she verbalizes the leap from energy conversion to existential threat, tacitly endorsing the Doctor’s resolution to act. Her earlier scientific curiosity curdles into unsettled resolve.

Goals in this moment
  • • Grasp the full scope of the crystal’s function and confirm the peril to Nyssa’s own satisfaction.
  • • Support the Doctor’s plan to intervene through Ambril despite the institution’s inertia.
Active beliefs
  • • Technological artifacts like the crystal reveal metaphysical truths when properly interpreted.
  • • Human institutions often fail to act until faced with irreversible evidence.
Character traits
analytical urgency moral clarity overriding wonder concise reasoning relentless deduction supportive urgency
Follow Nyssa's journey

Objects Involved

Significant items in this scene

1
The Great Crystal

The small, glowing blue crystal resting in the Doctor’s hands becomes the fulcrum of revelation. Its faint pulse of light underpins the Doctor’s deduction that thought can be converted into energy—and possibly matter—making it the key to either sealing the Mara away or enabling its return. He flicks it between his fingers as a physical metaphor for mental transformation.

Before: Freshly assessed, still warm from recent experimentation; now …
After: Still in the Doctor’s possession as he prepares …
Before: Freshly assessed, still warm from recent experimentation; now serving as a conduit of understanding.
After: Still in the Doctor’s possession as he prepares to depart the TARDIS with both artifact and urgency.

Location Details

Places and their significance in this event

1
TARDIS Central Control Chamber

The TARDIS control chamber serves as a compact laboratory of existential science, where the blue glow of the experiment’s aftermath mingles with the console’s eerie luminesce. The air hums with residual energy as Nyssa and the Doctor stand shoulder to shoulder, their collaboration framed by the ship’s curved walls—both a sanctuary and a launching point for urgent departure. Every detail is subordinated to cognition and crisis.

Atmosphere Electric tension underpinned by focused intellect and quiet dread
Function Field laboratory for desperate deduction and time-sensitive planning
Symbolism Represents the fusion of arcane knowledge and moral agency in the face of cosmic threat
Access Restricted to crew and invited agents of the Doctor’s choosing
The console emits narrow crimson and amber status lights in irregular patterns. A faint ozone tang mingles with lavender oils on the air.

Organizations Involved

Institutional presence and influence

1
Great Crystal Access Authority (Institutional Gatekeepers)

Director Ambril’s authority controls access to the Great Crystal, the very artifact the Mara requires to re-enter physical form. The Doctor perceives this institutional gatekeeping not as authority but as a desperate bottleneck. He gambles that reasoned urgency can pierce Ambril’s procedural rigor, transforming a bureaucratic obstacle into a critical hinge of salvation.

Representation Mediated through Ambril’s office and protocols—his decrees and sign-offs are the gate through which the …
Power Dynamics Institution exercises control over a cosmically dangerous artifact, but its representatives are slow to recognize …
Safeguard the crystal under established protocols and historical precedent. Maintain institutional face and avoid panic by controlling the narrative around the artifact. Restricted access via official channels and hierarchical permission. Control over knowledge dissemination and public interpretation of cultural artifacts.

Narrative Connections

How this event relates to others in the story

What led here 1
Causal

"After the Doctor and Nyssa analyze the crystal experiment and prove that thought can be transformed into energy, they immediately deduce the Mara’s plan: to use Tegan’s mind and the Great Crystal to manifest physically on Manussa."

Doctor races to stop Mara resurrection
S20E6 · Snakedance Part 2
What this causes 1
Causal

"After the Doctor and Nyssa analyze the crystal experiment and prove that thought can be transformed into energy, they immediately deduce the Mara’s plan: to use Tegan’s mind and the Great Crystal to manifest physically on Manussa."

Doctor races to stop Mara resurrection
S20E6 · Snakedance Part 2

Key Dialogue

"DOCTOR: Well, of course, it's small. It's power is obviously limited."
"NYSSA: And if the Mara's in Tegan's mind"
"DOCTOR: Exactly. The Mara needs the Great Crystal in order to make itself reoccur."