Object
Fifth Micro-Key
Physically used by Yartek to trigger the explosion in the Control Room; distinct from the Final Micro-Key, which remains in The Doctor's possession.
1 appearances
Purpose
Inserted into the Conscience machine to activate control over Marinus
Significance
Yartek thrusts it in, sparking the machine's detonation and building collapse. This blunder forces the Doctor's team into desperate flight, exposes Yartek's hubris, and shifts the conflict toward planetary chaos and final reckoning.
Appearances in the Narrative
When this object appears and how it's used