The first draft of Mind of Evil was written before the Master came along, so the original villain got rewritten into the Master.The Mind of Evil was an enjoyable 3rd Doctor story. It felt a bit long at times, but it didn't drag the story down. The Master, Doctor, Brigadier and Jo all did a good job, as they usually do. The Master's plan was decent, if a bit weird. I was a bit confused about something with the prisoners, though. Is it normal for England to put their prisoners in decent looking clothes complete with a collared shirt and tie? I guess in England, even violent criminals in jail need to look presentableI also liked the nods to Inferno, the Daleks and the Cybermen when The Doctor was mentally attacked. Overall, this was a very good story.
The next 3rd Doctor serial is The Claws of Axos, but I'm going to take a slight detour and watch my second ever 1st Doctor serial, The Aztecs. I've wanted to watch a well received 1st Doctor serial for awhile, since my previous experience with him was watching the fairly lackluster An Unearthly Child. After The Aztecs, I do intend to return to the 3rd Doctor.
In UK prisons some prisoners do get to wear civilian clothes. Not lifers like Mailer, but the clothes are accurate for the time (compare with the sitcom Porridge).
Some hasty rewriting was needed when the Army troops guarding the real missile they'd loaned (yep, it's real. Not a prop) turned up in uniform. So the Master and Yates discuss how they're mercenaries in fake uniforms.