Horizontal Escape Tunnel (Branching from Vertical Shaft)

Narrow horizontal tunnel branches from a vertical shaft midway through the Records Room, deep in Goodge Street's Underground base. Soldiers rigged it with explosives to eliminate the Doctor, but sabotage neutered the detonator—no blast occurred. Arnold exposes the tampering, fueling suspicions as Jamie and Travers debate the Doctor's survival and hiding spot. Damp stone walls trap cool air laced with damp earth and faint cordite, while echoes carry urgent accusations amid Yeti threats outside. Confined space amplifies betrayal's sting, turning escape route into accusation chamber.