The sixth Doctor always liked to "lord it" over Peri, and she never took kindly to this. However, the Doctor usually won, because he knew she couldn't be independent of him no matter how hard she tried because of her immaturity.

Living a life by the Doctor's side taught Peri sophistication (as well as strange little facts like how H.G. Wells came to write The Time Machine!), and she slowly lost her "know it all" attitude in favour of a more thoughtful frame of mind. This earned her a stronger bond of friendship with the Doctor. But as she became more thoughtful she also became more nostalgic and, over the course of her last three television stories, started becoming homesick.

Mindwarp, her last story, showed a confused Peri who felt betrayed by the Doctor when he suddenly turned against her. But given that the events we saw in that story were heavily edited (and in places changed) so as to show only what the prosecuting Valyard wanted the tribunial to see, then all we can be sure of is Peri found herself married to the besotted warrior King Yrcanos after apparently being killed off during a brain-transfer travesty. She never got to say goodbye to her Time Lord friend, and probably never knew why he just "took off" like that, abandoning her on Thoros-Beta. During the story she had built up quite a good rapport with the warrior King (played quite splendidly by Brian Blessed), but where she would ever have considered marrying him ..!

Nicola Bryant, in a Mythmakers interview during the mid-eighties, said that when the time came for her character to leave she wanted Peri to go out "with a bang; I just don't want to be married off to some space alien!" It is interesting to note that she managed to do both!

Still, before the events of his trial were over the Doctor would find himself with a new companion, Melanie Bush.

The idea behind re-introducing a schoolgirl-style character into the programme was to get the very young kids watching, and in particular the young girls. This led to features on the new Who companion appearing in the most unlikely of places - Sindy Comic, for example, had an interview with the actress about Mel's various costumes!

How Mel came to be travelling with the Doctor is something of a mystery. Terror of the Vervoids is the Doctor's defence during his trial, showing the Doctor in his own future saving the Earth - an event that would not happen if the Time Lords were to deny him the rest of his future lives. Mel is his current companion during this yet-to-happen adventure.

Mel is then taken out of time and place to be a witness at the Trial's conclusion. It is fair to assume that she had been taken from the end of the Vervoids tale because she already knew the Doctor well. However, at the end of the trial Mel the witness enters the Tardis as the new companion!

So when and where was Mel taken out of time from? Here's my theory: it was the same beam of turbulance that incarcerated Mel and Glitz, bringing them to the Time Lords cathedral-style trial space station. It was the Master who took them out of time. So suppose that Mel and Glitz were taken from just after Dragonfire. This would explain Mel's strange feeling about it being time that she left - with Glitz. Remember that the Doctor then said: "yes, you're going; you've been gone for ages; you're not really gone; you're still here; 'just arrived; I haven't even met you yet! It all depends on who you are and how you look at it. Strange business, time."

Nothing would please the Master more than to mess about with the Matrix and cause the Doctor's assistant, Mel, to be a temporal anomaly, locked forever in a timeloop. Why wouldn't the Time Lords save her? Well, their laws say they can't interfere ...

Despite having only been in nine stories, we know more about Ace than we ever learned about any other companion. We know Dorothy, as she was christened, didn't get on with her parents: "I ain't got no Mum an' Dad" in Dragonfire, and perhaps more subtly when Morgaine, in Battlefield, uses this part of her tormented mind against her via Shou Yuing who finds herself goading Ace with "I bet your parents hated your guts!"

In Remembrance of the Daleks she's keen enough on Sergeant Mike Smith until she learns of his racist beliefs. She takes more than a pale dislike to him then; iIn fact she is all ready to belt him one! Why? In Ghost Light we learn that racism led to the death of her friend Menesha.

Disturbed childhoods can lead to a tendency for explosives or havoc-making. After Menesha's death, and no doubt little consolation from her parents, Dorothy became Ace, and Ace became an arsonist, famed for the act of blowing up class 1C's prize-winning pottery pig collection when at school (her story in Battlefield).

During one of her experiments with explosives, a "time storm" blew up and carried her off to a planet called Iceworld. Yeah, right! But this daft explanation (no doubt inspired by that other famous Dorothy) was to become frighteningly relevant in a future story.

Anyway, it is on Iceworld that Ace encounters the Doctor. She's a rebel, he's a rebel Time Lord; they hit it off famously. But the Doctor has ulterior motives for taking her on board ...

It was when he took her to the psychic circus in The Greatest Show in the Galaxy that we first saw how he was making her face some of her hang-ups. Ace found clowns creepy. She didn't want to go. "Of course, if you're scared ..." the Doctor said, his voice trailing off. It was enough. Ace wasn't scared. Dorothy was quaking in her shoes, but Ace wasn't scared - honest! By the time that she faced the clowns she realised that they were only robots. The robots were out to kill her, but she could handle that.

Then in Ghost Light she tells the Doctor of her nightmare. A horror from her past. Something inside an old empty house. Something evil. She never found out what it was. She simply blew the house up. But having blown it away without knowing what it had been she was still having nightmares about what the evil might have been. Even after she had faced a sorceress (Morgaine), she was still haunted by this house, and the evil that she had sensed inside ...

After telling the Doctor, she finds that he has taken her to that very house, Gabriel Chase, 100 years before she blew it up. When it was occupied. Occupied, by the evil.

The Doctor makes her face her fears, cleanse her guilt, win her over. From what you may ask. Ah! The Curse of Fenric. The ulterior motive.

In a previous time, a previous place, the Doctor had played a game of chess with Fenric, an ancient evil. The prize was freedom. Fenric lost control of the game, so Fenric lost its freedom and found itself chained in the shadow dimension. However, Fenric's evil had infected Viking men with it's curse, and that curse was passed onto the Vikings' sons and daughters in turn, though the decendants, all the way down the line to Ace.

Fenrics move had been to send Ace to Iceworld (the time-storm) as it's pawn, by the Doctor's side; waiting. But the Doctor had guessed this. The chess set and the positions of the black and white pawns in Lady Pienforte's study had been the clue, in the story Silver Nemisis. So he started working at turning Fenric's pawn into his own pawn, ready for the final game which could be anywhere in Ace's ancestry, for all her ancestors would be infected with the curse, surrounding the Doctor with Fenric's unknowing pawns.

Knowing that the game will be played in Ace's past, the Doctor picks a time and place that will be beneficial to her; a place where she can unlock another pocket of guilt. 1943. A baby called Audrey. The undercurrent feelings against her mother, Audrey, appear. But it's Ace's love for the baby that surfaces. In the final scene she washes herself free of the guilt, and of the curse of Fenric.

And then in Survival, the last TV story broadcast until 1996, we saw how the influence of the Hunting World brought out the animal in Ace. But while the Masters animal instincts were always to kill, Ace's instinct was to run like the wind and be free. But with the Tardis and the Doctor she could run like the wind and be free - of guilt. With this she could deny the instinct of the Hunting World before it devoured her. To survive you didn't need muscle so much as you needed wit, wisdom and a good strong pair of legs!

And eventually, as adrenaline can burn out a person, the planet's adrenaline (fire and volcanoes) burned out and erupted the planet; freeing all those it had infected of it's infection.

The last we saw of the Doctor and Ace was as they walked back up hill to their home, the Tardis, while the Doctor pointed his trusty brolly skyward promising Ace new worlds, new dangers, and new tides of injustice to fight. This was surely the finest season-ending we ever saw, promising great things for season 27. But, alas, this was the last we were to see of Dr Who for six years, and the last we were to see of Ace - the third companion who never got any kind of proper leaving scene.