The Doctor, Turlough and Tegan are on the planet Melphis, in a very different genre of the galaxy to the one the Doctor usually inhabits. They agree to do a favour for DaSamPete, "the three headed man".
DaSamPete has lost his robot and he wants them to find it for him.
He handed the Doctor a small plasti-flex disc that carried a moving 3-D computer portrait of a squat robot with long heavy arms.
"Has he got a name?" asked Turlough.
"He's a Class 4 Subsection B - with modifications," said DaSamPete.
The Doctor, Turlough and Tegan are given flying chairs to travel about in. They go to "Melphis's one and only city".
The city was teeming with all sorts of life forms and in the courtyard of one market alone the Doctor recognised Stullubrian warriors, Mdimian traders and var-ious nomadic species.
They go to a "Robo-Mart" where the Doctor bribes a walnut for information.
"Have you seen any Class 4s around here?" the Doctor asked. The machine didn't answer. The Doctor put a red credit disc into the slot next to the walnut. A light went on and a soft, female voice came out of the synthi-voc. "A Class 4 Subsection B?" it said.
I quite like this picture because the Doctor, Turlough and Tegan are all recognisable from their silhouettes, although going by all the pictures so far I think the artist is just trying to avoid having to draw any of their faces.
They go to the "Southern Free Zone".
Free Zones were walled sections of large cities where the normal rule of law was suspended. they were usually rundown areas populated by thieves, runaways, murderers, malfunctioning robots and mutants of every shape and hue.
Avon's right, this does sound like Gauda Prime, except that it isn't the whole planet.
The Doctor helps repair a Class 2 Domestic robot in return for information, acting more like Avon than the Doctor should ever be. The robot tells him that the Class 4 robot they are looking for was trying to sell "Antherack."
In a vague attempt to make this seem more like Davo-era Doctor Who, Tegan and Turlough have an argument.
"It's not exciting, you imbecile!" Tegan said scornfully. "It's a waste of our time!"
"No, it's not!" said Turlough. "It's good fun. By the way, Doctor - what's Antherack?" The Doctor slowed down his Hovva-Hoppa [flying chair - ed].
"It's an illegal energy source," he explained.
They are too late though, as the robot tells them that mannys working for "The Brothers", also known as DaSamPete, already found the Class 4 and took him away. This twist to the story is handled very clumsily, delivered as pure exposition from a single informant as if it were the shoe-shining manny from Police Squad.
This whole page is very confusing - the Doctor uses technobabble to somehow find out that DaSamPete "are notorious smugglers" of Antherack. The Class 4 robot found their buried stash and decided to sell it in the Free Zone. Now that DaSamPete has been revealed to be a baddy and has captured the Class 4, the Doctor decides to stop him and they rush straight to "DaSamPete's recycling factory".
In the dramatic climax to this story, the artist can no longer postpone the inevitable moment when he has to draw the Doctor's face. So he has drawn it really small, with Turlough's half-hidden behind some steam and Tegan nowhere to be seen.
The Class 4 robot is (I have to presume) being interrogated by DaSamPete, by being held above a "boiling acid vat". The Doctor just has time to confront DaSamPete before the robot pulls the platform, itself and DaSamPete into the acid, killing them both and rendering the entire story completely pointless because it means the Doctor's presence and participation changed or accomplished nothing at all.
There only remains for the obligatory final joke to take up the last couple of paragraphs:
There was a growl of machinery behind them, a loud metallic belch, and a small ball of undissolved metal rolled out of a pipe near the base of the vat.
"The Class 4 Robot - or what's left of him," explained the Doctor, holding up the jet black lump.
"Can I keep it?" asked Tegan.
"Why?" asked Turlough. "Don't tell me you're getting senti-mental about a criminal robot."
"Not exactly," said Tegan, "I just thought it would make a pretty good paperweight."
Mew, that is the end of this awful story. It is so bad because of a combination of two reasons, either of which could have been forgivable by itself. The first is that the Doctor doesn't really doing anything throughout except for acting out of character, or to put it another way there is nothing in the characterisation that makes this feel like a Doctor Who story. The second is that the setting feels as if it belongs to a different kind of science fiction from the kind that belongs in Doctor Who - it is the sort we see in Blakes 7 or Star Trek V: The Final Frontier's Planet of Galactic Peace, being filled with criminals - there is nothing in the setting that makes this feel like a Doctor Who story.
Contrast this with the TV serial Caves of Androzani, which has its share of androids and criminals too, but the way they are used, and the way the Doctor and Peri interact with them and react to the events, makes all the difference.