Jo Grant's struggle to survive the prison riot and the Master's manipulations.

In the escalating chaos of the prison riot, Mailer seizes control by violently forcing Jo Grant and Doctor Summers up the stairs at gunpoint, ignoring Summers’ protests and Vosper’s warnings …

The Doctor is forcibly escorted into the Governor’s office by Mailer and Vosper, only to find the Master—disguised as Professor Keller—now in complete control of Stangmoor Prison. The Master reveals …