Inside the Pyramid

Susan leans against the pyramid's seamless stone wall, triggering a hidden slab that drops open beneath her. She vanishes screaming into the dark depths below, pulled into this mysterious interior. Moments later, the Doctor rushes to the sound and suffers the same fate, yanked through the trapdoor. The space traps them without explanation, its dangers amplified by echoing cries and sudden isolation, forcing Ian and Barbara to confront the pyramid's lethal secrets from outside.