On the planet Varos, prisoners and guards alike are subject to severest forms of punishment, which are then broadcast to the masses as entertainment.

For the Doctor, Varos is the only hope for him to locate the rare mineral Zeiton-7 to power his ailing TARDIS. Arriving on Varos, he and Peri are soon caught up in events beyond their control.

Freeing the rebel leader Jandar (Jason Connery) and incurring the wrath of the sinister alien Sil are just the beginnings of their ordeal. Hunted through the concealed terrors of the Punishment Dome, the Doctor becomes the subject of Varos's latest TV entertainment. this is one show where he may not survive beyond the cliffhanger.