Doctor Who (1963)

S14E5 The Hand of Fear (1)

In a near-future England, the TARDIS appears in a quarry where Sarah finds herself pinned beneath a pile of rubble. As she struggles, a fossilized hand is discovered clutched in her grasp. The mystery deepens with her repeated mention of someone named Eldrad. Who is this figure, and what connection do they have to Sarah's predicament?