In the introductory episode of the series, the presence of several street gangs contributes to a tension-filled atmosphere. The Rookies are assigned with the challenge of maintaining order amongst the rivaling street gangs, with Willie Gillis arising as the mediator between the gangs.
Finding themselves lost in space aboard a spaceship, the Pussycats land on the planetoid Zelkor and encounter a creature named Bleep. Then they find out that Josie has been kidnapped and replaced with an android!
The Crown Jewels have disappeared from their case.
When the Mystery Machine breaks down near The Three Stooge's ghost town theme park, the gang try to figure out who's been sabotaging the Stooge's rides and running away the tourists.
The Doctor enters the labyrinth to try and protect Jo from the minotaur but the Master has seized control of Atlantis and prepares to summon Kronos again.
Both TARDISes reach Atlantis, where the Doctor befriends King Dalios while the Master enlists the help of Queen Galleia to try and obtain the crystal of Kronos.
The Master prepares to travel back to Atlantis but the Doctor links his TARDIS to the Master's to try and stop him.
The Master enlists the help of Krasis to control Kronos while Yates tries to bring the TARDIS to the institute only to come under attack from dangers from the past.
The Doctor realises the Master is trying to harness the power of Kronos, last of the Chronovores, but is unaware Percival is harbouring him at the institute.
When Joan decides to make herself more attractive to her husband Eddie, she little realises that it will start off a chain of events which will bring the uneasy truth between them and Barbie and Bill into open warfare.
UNIT are invited to observe a demonstration of the new TOMTIT machine, unaware its creator, Professor Thascales, is actually the Master.
Despite the fact that Eddie is a staunch socialist and Bill is a true blue Conservative, there are many subjects on which they both agree. For instance, they are both against discrimination. When Bill tells Eddie that he was once refused a drink in a pub because of his colour, Eddie's British sense of justice and fair play is outraged and he sets out to prove that the opposite must be the case, with rather painful results.
The Doctor is forced to help the Marshal cover up his actions with the Investigator but Jo and the others attempt to escape to expose him.
There comes a time in every husband's life when he is tempted to stray from the marital home: and Eddie and Bill are no exception - for the seven year itch has no colour bar. However, the trouble with an itch is that one is tempted to scratch it.
The Marshal's premature use of Jaeger's experiment is threatening to destroy Solos' atmosphere and the Doctor returns to Skybase to try and correct the damage.
An industrial dispute between Eddie and Bill at the factory causes a domestic dispute with their respective wives, Joan and Barbie. However, blood is thicker than water - as Eddie learns to his cost.