Internal Betrayal: The struggle to identify and neutralize a traitor within Goodge Street HQ who is aiding the Great Intelligence.

Amidst the frantic preparations to counter the Great Intelligence’s advancing threat, an unseen figure moves stealthily to the main door of the Goodge Street Ops Room and unbolts it, leaving …

The Doctor confirms the explosives' 60-second timer to Colonel Lethbridge-Stewart, but the moment is shattered when Staff Arnold reports the unsecured main door—a critical breach in their defenses. Before the …