|Doctor Who-The Sea Devils|
While visiting the Master in a maximum security island prison,it's learned that he's actually pulled the wool not only over the doctor and Jo Grant's eye but the prison staff itself. Meanwhile a series of ships are being mysteriously sunk. And the only connection each time remains the wily Master. Surviving crew members of these ships soon begin to talk of creatures from the ocean being involved. By the time the doctor has applied his usual scientific and physical actions to investigate he discovers a race of aquatic lifeforms who were present on Earth during the same time as the Silurians. Making the same argument on sharing the Earth with humans, the Master tries to convince the doctor and the Sea Devils that humans aren't to be trusted.
It turns out the Master's words are unintentionally headed an over zealous Royal Navy plans to handle the situation,in the absence of UNIT,with a nuclear based retaliatory strike. For a time the doctor and the Master are again forced to put their heads together to find another answer out of the situation. While the discover one that seems to work,in this case by "reversing the power of the neutron flow" yet again,the ensuing explosion almost ends with both time lords getting killed without much hope of regeneration. At the same time,on a number of levels,it does appear that from beginning to end the Master had been manipulating both the Navy and Sea Devils into some cat and mouse game that could at some future time resume.
While not as broadly based a story as 'The Silurians',this story mainly provides a catalyst by which the two opposing time lords could match wits. In one scene the doctor and the master actually engage in a rapier dueling match. This is no mere good versus evil story. In fact the Master is not 100% villainous and emerges more as an opportunistic manipulator. Most of his actions are based purely in his egoist attitudes that humanity are hopelessly inferior. And their impulsive actions,especially in this serial often prove him right in the short term. But the Masters dim and cynical view of other races aside from his own is matched by the doctors almost eternal hope and optimism. This boils down to a pitch battle between this two disparate egos. And the "monsters" involved,the Sea Devils are presented here mainly as being caught in the middle.