Doctor Who: Underworld (Part 4)

"Underworld (Part 4)" is the fourth and final chapter in the "Underworld" serial, which ran through episodes 5-8 in series 15 of the television series Doctor Who. The episodes originally aired in four parts on BBC1 from January 7th to January 28th, 1978. The serial was directed by David Maloney and written by veteran Doctor Who screenplay writer Terry Nation. In this episode, The Thal resistance fighters storm the Kaled bunker. The Doctor faces a strong moral dilemma and Davros makes his final move as the Daleks patrol the bunker corridors wiping out all opposition.