Synopsis: The Master arrives on Earth stealing the Nestine Consciousness and planting himself in a plastics factory.
This is the first time we meet The Master, an old childhood friend of The Doctor’s, who has turned evil.
It’s also the first time we encounter Time Lords other than The Doctor since War Games. There’s both The Master, and another Time Lord pops in to warn The Doctor wearing a bowler hat and suit. Not the most Time Lordy outfit.
We don’t know much of The Master’s intentions, but he is intent on causing disruptions in the lives of humans and The Doctor.
We are also introduced to Jo Grant. Liz is suddenly gone without explanation, and instead we are introduced to a young woman eager to be The Doctor’s new assistant. Jo Grant is a funny looking woman wearing a mullet a la Linda McCartney. She’s an idiot. She’s boring. And most importantly, based on this one story, she’s a horrible companion compared to Liz.
Liz was intelligent, and challenged The Doctor. Liz was skeptical and humorous.
Jo is stupid.
In this story, The Doctor once against must face the Autons. A race of plastic people that are the precursor for the Nestine’s invasion of Earth. The Master is helping them out.
This leads to one of the worst endings in Doctor Who history. Our buddy The Master is excited that the plan is working, and the Nestine are about to arrive. The Doctor tells him that they won’t distinguish between The Master and the humans. The Master looks alarmed and suddenly helps The Doctor.
Of course, their solution is to “reverse the polarity.”
It’s an awkward ending.
The Master escapes, but can’t get far, as The Doctor had stolen his dematerialization circuit, which unfortunately does not work in The Doctor’s TARDIS.
The ending feels like it needs The Master to shout out, “I’ll get you next time Gadget, next time!”