S20E14 · Terminus Part 2 graph

Gas fills corridor forcing desperate flight

The space liner’s corridors are overtaken by noxious gas as Terminus activates its lethal sterilization protocols. Kari’s warning arrives just in time for the Doctor to identify the threat as stage two sterilisation, forcing the pair to abandon their search and flee into Terminus’s shadowed depths. The lethal gas underscores the station’s murderous design while accelerating the companions’ transformation from investigators to hunted fugitives. This marks a pivotal escalation where the station’s hidden horrors become an immediate, inescapable danger. key_dialogue: [ KARI: Gas is beginning to enter the corridor. DOCTOR: Stage two sterilisation. Come on! ]

Plot Beats

The narrative micro-steps within this event

2

Tegan alerts the Doctor to a potential threat, and Kari notices gas entering the corridor, indicating a dangerous situation.

calm to concern ['corridor']

The Doctor identifies the gas as part of 'stage two sterilisation', prompting urgency to escape.

concern to urgency

Who Was There

Characters present in this moment

3

Urgently focused with underlying tension, masking personal concern for safety

The Doctor actively listens to the urgent call from Tegan before swiftly identifying the gas presence as stage two sterilisation. He reacts with immediate urgency, pivoting from investigation to escape and urging Kari to follow without hesitation.

Goals in this moment
  • Assess the immediate environmental threat to the corridor
  • Ensure Kari’s escape alongside his own
Active beliefs
  • The station is actively hostile and lethal
  • Swift action is necessary to survive its systems
Character traits
Methodical under pressure Protective instinct Rapid diagnostic ability
Follow The Fifth …'s journey

Sharp alertness rapidly escalating to urgent self-preservation

Kari detects the hazardous gas entering the corridor and immediately alerts the Doctor, pointing out the danger before it fully engulfs them. She combines observational alertness with decisive action to escape, embodying leadership amid peril.

Goals in this moment
  • Warn companions of the immediate danger
  • Secure a path to safety with the Doctor
Active beliefs
  • The station’s systems prioritize lethal decontamination
  • Trust in the Doctor’s guidance for survival
Character traits
Observational precision Strategic adaptability Alert responsiveness
Follow Kari Olvir's journey
Supporting 1
Tegan Jovanka
secondary

Anxiously urgent to avert danger before it escalates

Tegan calls out urgently to the Doctor from an off-screen vantage point, attempting to get his attention before the gas overtakes the corridor. Her voice represents the immediate alarm signaling the onset of the station’s lethal sterilisation protocols.

Goals in this moment
  • Alert the Doctor to the immediate threat
  • Ensure his movement to safety
Active beliefs
  • The Doctor must know of the danger immediately
  • The station’s environment is deteriorating rapidly
Character traits
Insistent urgency Presence through voice only Loyal concern
Follow Tegan Jovanka's journey

Location Details

Places and their significance in this event

1
Terminus Space Liner

The Terminus space liner’s corridors become a death trap as toxic sterilisation gas floods the passageways, reducing visibility and threatening life. The failing ventilation and rusted infrastructure amplify the lethality, turning a once-utilitarian route into a claustrophobic escape route. The station’s systems actively turn against those within it, mirroring its hidden murderous agenda.

Atmosphere Ominous and suffocating with a metallic tang of chemical agents
Function Conduit of imminent death morphing into an escape challenge
Symbolism Embodiment of Terminus’s ruthless, programmed hostility toward life
Access Open but lethal due to gas contamination and automated decontamination systems
Toxic sterilisation gas entering through ventilation Flickering strip lighting casting sharp shadows amid the haze

Narrative Connections

How this event relates to others in the story

Within this episode

What led here 1

"The Tannoy's warning of 'stage one sterilisation' directly causes the Doctor's urgency to escape, which later escalates to 'stage two sterilisation' (gas). The Tannoy's announcement is a pivotal moment that transforms the story from investigation to survival."

Sterilization alarm forces hasty escape
S20E14 · Terminus Part 2

Across episodes

Threads arriving here 1
Causal medium

"Turlough’s sabotage of the TARDIS in Episode 13 causes the TARDIS to become unstable, which is mirrored by the space liner’s own systems failing catastrophically in Episode 14 due to Terminus’s sterilization protocols. The Doctor's ability to diagnose the gas threat in Episode 14 follows his recognition of systemic sabotage in Episode 13."

Doctor exposes Turloughs sabotage
S20E13 · Terminus Part 1
Threads leading onward 1

"The Doctor and Kari’s attempt to escape the liner due to the gas filling the corridor (Ep 14) leads directly to the Vanir’s forced relocation of Lazars (including Nyssa) to Tank Three in Terminus (Ep 15), reflecting the escalation of Terminus’s violent systems."

Sigurd orders Olvir to relocate the Lazars
S20E15 · Terminus Part 3

Part of Larger Arcs