Tarak's Rasputin-esque layered betrayal masking deeper loyalty to the Doctor and Romana's mission, and the consequences of his exposed deceit within the Tower's institutional security.

Tarak attempts to exploit a guard changeover to secure the Doctor and Romana’s escape but is immediately recognized by the veteran sentinel. The guard’s recall of Tarak’s rebel history ignites …

Romana stumbles upon a critical clue linking the Record of Rassilon to Type 40 time vessels just as the Doctor connects this to the TARDIS. Their fragile plan to research …