Classic Doctor Who Season 8 Episode 8 The Mind of Evil: Part 4

The Doctor and UNIT are still grappling with the mysterious machine that has the power to drain people's minds. Meanwhile, a dangerous criminal known as the Master has been smuggled into a high-security prison to retrieve a device that will enable him to control the machine. With the Master on the loose and the machine set to self-destruct, the Doctor must race against time to stop both threats and save the lives of his companions and the people of Earth.

In the previous episode, the Doctor and Jo Grant had discovered that the Mind Parasite was actually a machine that had been reprogrammed to drain the energy of the brains of the people it encountered. The Brigadier had meanwhile been dealing with the political fallout of the situation, as the Russian and Chinese ambassadors had been affected by the machine and were now accusing UNIT of being involved in the plot.

As this episode begins, tension is high as the Doctor tries to convince the Brigadier of the seriousness of the situation. But the Master's arrival soon throws everything into chaos. He has managed to infiltrate the prison by posing as a clergyman, and he quickly sets about retrieving the device that will allow him to control the Mind Parasite.

The Doctor and Jo are alerted to the Master's presence by a terrified prison guard, but they arrive too late to stop him. They follow him to a laboratory, but he has already activated the device and is now in control of the machine.

Now faced with two major threats, the Doctor quickly formulates a plan. He and Jo will try to find a way to stop the Mind Parasite from self-destructing, while the Brigadier and his team will deal with the Master and his minions.

As the Doctor and Jo delve deeper into the workings of the machine, they discover that it is actually a gateway to another dimension. They also learn that the only way to stop the self-destruct sequence is by using a set of special codes.

But as they search for the codes, they are ambushed by the Master's henchmen. A tense showdown ensues, with the Doctor and Jo barely managing to hold their own against the armed intruders.

Meanwhile, the Brigadier and his team are battling their way through the prison, fighting off the Master's minions and trying to reach their colleagues before it's too late. They manage to capture the Master, but not before he has set the machine to overload.

With time running out, the Doctor and Jo finally manage to crack the code and shut down the self-destruct sequence. But the Master is still at large, and he is not ready to give up his plans to control the Mindscape just yet.

As the final confrontation approaches, the Doctor and his companions must use all their wits and strength to stop the Master's schemes and keep the world safe from the power of the Mind Parasite.