Fabula
Object
Object

Great Key of Rassilon

A short rod of black, glassy material, its surface catching the dim light with a dull metallic sheen. The Doctor handles it with deliberate care during tense deductions, recognizing its latent function beyond ceremonial status. Its simplicity belies its lethal potential—when activated, the Key emits no visible spark but triggers unseen molecular processes, the mechanism hidden within its unassuming length.
3 appearances

Appearances in the Narrative

When this object appears and how it's used

3 moments
S14E24 · The Talons of Weng-Chiang Part 4
Doctor unlocks cabinet’s dark truth

Though the Great Key of Rassilon is not physically present in this event, it is referenced as the critical component needed to operate the cabinet. The Doctor's deduction about its necessity transforms the discussion from social banality to urgent conspiracy.

Before: Existed beyond the scene, held by Weng-Chiang as part of his temporal apparatus
After: Remains in Weng-Chiang's possession, now identified as essential for controlling the lethal cabinet
View full event
S14E12 · The Deadly Assassin Part 4
Doctor uncovers Masters staged death plan

The Great Key of Rassilon surfaces in conversation as Engin lists the symbols of the Presidency, triggering the Doctor’s realization that these artifacts may be instrumental in the Master’s scheme. Like the Sash, it remains off-stage but central to the Doctor’s emerging theory about power and manipulation.

Before: Stored as part of the ceremonial regalia, typically carried by the President during rituals
After: Unchanged in location, but its relevance is heightened by the Doctor’s growing suspicion of its functional, not merely symbolic, role
View full event
S14E12 · The Deadly Assassin Part 4
Doctor learns Eye of Harmony secrets

The Great Key is referenced in the historical transgram as the instrument Rassilon used to seal the Eye of Harmony. The Doctor’s question—'What’s the Great Key?'—sharpens the mystery of its ceremonial function. It becomes a pivot point for understanding the Master’s potential manipulation of these artifacts.

Before: Regarded as a mere ceremonial relic
After: Identified as a functional artifact of immense power
View full event