The Doctor and Jo visit the Master at his island prison where the Doctor becomes curious about a number of ships sinking in the area.
Did You Know?
The sea fort setting was a late change to the scripts. Malcolm Hulke
had originally written this material for an oil rig, but Michael E. Briant
was unable to obtain permission to film on one. See more
The BBC wish to acknowledge the help given to them by the Royal Navy in the making of this programme See more
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