The Doctor and Ace

In a quiet suburban street a man is washing his car when something unseen appears before him. He tries to run, but suddenly vanishes. Shortly afterwards the TARDIS arrives at the end of the street and The Doctor and his travelling companion Ace exit. The Doctor has brought Ace back to present day Perivale, London so that she can revisit old friends. They head for the youth club where Sergeant Paterson, who has been teaching the art of survival to a group of lads, tells them that kids from the area keep vanishing. The Doctor though is more concerned by a black cat that seems to be watching them.

The Doctor and Ace then go to Perivale High Street where The Doctor buys some cat food and cheese from a supermarket run by Len and Harvey. It is there that Ace bumps into one of her friends, Ange, who tells her that she hasn’t seen any of the others lately. Ace is worried about the unexplained disappearance of most of her old friends, but The Doctor is more preoccupied with the behaviour of a strange cat. He wanders off and opens some cat food in the street and then hides in a front garden and waits as it has become apparent to him the black cat is being controlled by a strange being in another dimension, viewing the scenes in Perivale through the cat’s eyes and choosing which humans to chase and transport.

Meanwhile Ace makes her way to a children’s play area. She finds a black cat and, after it runs off, is suddenly confronted by a humanoid Cheetah Person on horseback. Ace is chased around the play area and shouts for The Doctor. Suddenly there is a flash of light and Ace finds herself on an alien planet, where she discovers the dead body of the man seen earlier washing his car. Ace is again chased by the Cheetah Person on horseback but manages to get away with the aid of a boy, who is killed and taken by the Cheetah Person. Ace then meets her friends Shreela, Midge and Derek who are hiding out and, on learning from them that they had been transported to this alien planet and are being hunted by the Cheetahs, she becomes determined to go on the offensive.

The Doctor Shopping for Cat Food

On having heard Ace’s call for help The Doctor arrives to find the children’s play area deserted and deduces that Ace has been transported away. He returns to his bait and sees a black cat, which he pursues but is hampered by Sergeant Paterson, who chases after him in the belief that The Doctor is causing a public nuisance. When The Doctor climbs a wall to get to the cat Sergeant Paterson catches up with him and they both fall from the wall and arrive on the alien planet which has a blood-red sky. They find themselves in the middle of the Cheetah People’s camp and being herded towards a tent. The Doctor pulls back the flap of the tent to find, seated inside his arch enemy, The Master. The Master’s eyes glow yellow and he comments that The Doctor’s arrival is an unexpected pleasure.

The renegade is evidently unwell, his eyes and mouth displaying feline characteristics. The Doctor resists The Master’s attempts to goad him into running, but Sergeant Paterson is not so strong willed and is caught and tormented by the Cheetah People. The Doctor manages to grab a horse, rescue Sergeant Paterson and escape. But they soon get caught in a trap set by Ace who had intended to capture a Cheetah Person.

Visiting Perivale

Reunited with Ace, The Doctor is determined to get everyone to a safe area beyond the Cheetah People’s camp and explains that the planet is on the point of breaking up. Warning them not to run, he starts to lead them through an area containing a number of Cheetah People. Suddenly a milkman appears, exciting the Cheetah People and panicking the humans. Everyone but The Doctor runs, and the Cheetah People attack. In the confusion Ace manages to capture a horse and she soon finds herself by a lake watching an injured Cheetah Person arrive on the other side. It collapses and Ace goes to its aid, speaking to it and bringing it water from the lake.

Meanwhile The Doctor encounters The Master by some ruined buildings. The Master explains that the Cheetah People are linked to the planet and when they fight each other, they bring it closer to destruction. He wants The Doctor to find a way out of the situation. He himself having been infected by the planet and so is gradually transforming into a cheetah person. The Doctor then leaves The Master and finds Ace. He and tells her that they need an animal whose home is Earth in order to return there. The Master overhears this and prepares a leash by stripping some skin from a dead animal. Ace confesses to The Doctor that she likes the planet and feels as if she could run forever. She is also starving hungry. They meet up with the others. Midge attacks Derek but runs off, his eyes glowing yellow, when The Doctor intervenes. Midge encounters The Master who puts him on the leash and tells him to go hunting. He vanishes, taking The Master with him.

The Doctor tells Ace and the others that they must wait until one of them succumbs to the planet’s influence and then use that person to get them home. The Cheetah Person, that Ace helped by the lake, appears which pleases Ace. However, when Ace looks back at The Doctor her eyes are glowing yellow. The Cheetah Person then asks Ace to come hunting and they run off together, a perturbed Doctor giving chase.

The Master

Ace speaks to the Cheetah Person, learning that it is called Karra. Ace also wonders why Karra called her ‘sister’. She sees her yellow-eyed reflection and realises that she must get back to The Doctor. Karra tempts her with the hunt for food, but she resists this and returns with The Doctor to the others. The Doctor explains to Ace that if she helps them to escape, she may never change back. They all link hands, and Ace transports them back to Earth. After Shreela and Derek run off, and with Sergeant Paterson refusing to acknowledge that anything out of the ordinary has happened, Ace announces that she wants to leave in the TARDIS but The Doctor insists they need to sort out The Master and Midge. They visit Midge’s home and find a slaughtered cat and a young girl, called Squeak, who shows them the direction in which The Master and Midge went. Ace’s eyes glow yellow again, and she senses that Midge is at the youth club.

The boys at the youth club have been hypnotised by The Master, and when Sergeant Paterson arrives they kill him. The Doctor and Ace catch up with them on a nearby hill. There she witnesses The Doctor and Midge confront each other in a motorbike duel, riding directly at each other at high speed. There is a massive explosion as the bikes collide. Midge dies after the crash, but the only trace that Ace can find of The Doctor is his hat. The hypnotised boys approach, but she realises that she cannot fight them – The Doctor having earlier warned her that if she does so she will be permanently transformed. In desperation she calls for help and to her surprise Karra appears on horseback and chases the boys away. But to Ace’s horror, when Karra dismounts, The Master stabs Karra with an animal tooth. The Master then leaves, passing The Doctor’s body lying in a rubbish heap. The Doctor though is still alive and, on recovering, he returns up the hill where he spots Ace crying over Karra, who has transformed into a young woman. Karra wishes Ace good hunting and then dies.

The Doctor then encounters The Master waiting for him by the TARDIS. The Master is still infected and feels the power from the planet growing in him. He grabs The Doctor and they are both transported back to the Cheetah Planet, which is visibly more unstable than before. They struggle with each other, but The Doctor realises that they must stop. The Master claims that they cannot escape and goes to deliver the fatal blow. At the last moment however The Doctor is suddenly transported back to Earth. He finds himself by the TARDIS being berated by a housewife about the noise of his shouting.

Meanwhile back on the hill Ace looks on as another Cheetah Person appears on horseback, picks up Karra’s body and then vanishes again. Then to her relief The Doctor arrives and after retrieving his hat and umbrella from Ace he tells her that the Cheetah Planet will live on inside her. They then both turn and head back towards the TARDIS and for new adventures.