However, those stories weren't the only Colin Baker stories that fell by the wayside. Here we have Leviathan, a story written by the late veteran TV writer Brian Finch for season 22. Despite getting as far as a rehearsal script, the story never got made, probably because it would have been too damn expensive to make.

In the story, the Doctor and Peri land in a medieval forest near a castle. They come across some villagers who are being pursued by Herne the Hunter.

Cue the Celtic charms of Clannad and the theme to Robin of Sherwood? No, because this Herne is mean and he's out for blood…

Now Big Finish can be a little off the wall sometimes, but usually they're quite conventional. However, this time – for three plays only – they've done something that I bet Steven Moffat never, ever considered: they've given him a racist, fascist, time-travelling Nazi scientist as an assistant. Yeah, beat that Stevie, you no-talent hack.

For those of you who haven't been listening to the Big Finish plays for the last decade or so, Colditz has probably slipped under your radar, especially since it's a Seventh Doctor/Ace play, so likely to be languishing at the bottom of any collection/bargain bin. Just to jog your memory, it's the one with David Tennant doing the bad German accent.

You probably won't recall the actual plot, however, so let me remind you: the Doctor and Ace land in/near Colditz; they do lots of dumb things; the Nazis capture them and the TARDIS; a Nazi scientist called Klein takes the TARDIS into the future where the Third Reich have won the Second World War; through timey-wimey machinations the alternative future gets undone, Herr David Tennant gets killed off, and Klein is left lurking around somewhere in the world, possessing knowledge of science and the alternative future that she shouldn't have.

A Thousand Tiny Wings picks up where Colditz left off by plopping the companionless Seventh Doctor down into 1950s Kenya at the time of the Mau Mau uprising. Here he comes across a bunch of posh English people stuck in a house and slowly being killed off by a mysterious poison. And Dr Elizabeth Klein.

Sounding good yet? No? Thought not.

Yet, despite sounding extremely bad on paper, it's actually a pretty decent play in practice.

Set during the reign of the Fifth Doctor, Ringpullworld in no way attempts to fit in. It doesn't feel like Doctor Who at all, at times. However, this isn't necessarily a bad thing, because if you squint a bit, you could actually imagine this was written by Douglas Adams, since it's probably the cleverest and most entertaining of all the Companion Chronicles so far. It really is that good.

Funny that it's about Turlough, mind.

Instead, let's talk aboutThe Pyralis Effect, starring Lalla Ward as Romana II. Now, despite the fact almost everyone loves the Fourth Doctor, most of the Companion Chronicles featuring him and his various assistants have been terrible, whether they feature Leela, Romana I or Romana II.

But, as you might have noticed, over series three of The Companion Chronicles and as we've gone through series four, the whole range began to get much, much better. So should it surprise you much to hear that, in contrast to those previous Fourth Doctor Chronicles, The Pyralis Effect is actually pretty good?

When we last met him in the Big Finish plays, it was for a Companion Chronicle, Helicon Prime, which - to put it bluntly - was absolute rubbish. To be fair, until recently, all the second Doctor Companion Chronicles were rubbish, so Helicon Prime wasn't on its own for this quality shortfall. But it was rubbish.

Nevertheless, despite this inauspicious return, Jamie's back in a big way - Big Finish intend to have him in a two-handed Companion Chronicle with Deborah Watling as Victoria in March, and as a companion of the Sixth Doctor in a forthcoming trilogy of plays (one of which will also feature Wendy Padbury as Zoe) and a Companion Chronicle.

So you might have been expecting this play, in which an agent of the Time Lord's Celestial Intervention Agency gives Jamie back his memories of his time with the Doctor, to be the launch of this Jamie range.

Wrong.

Instead, we have a pretty good historical story - with just a hint of sci-fi - set during England's Glorious Revolution.

First up is The Drowned World, which is a follow-up to surprise hit Home Truths, starring Jean Marsh as Sara Kingdom. Home Truths is probably the best Companion Chronicle of the last three seasons, which, given it was about a character that might not even be a companion, was something of a surprise.

The question is: will the follow-up be as good?

But as I've said before, sometimes there have been good reasons for stories not getting made. For example, apart from production difficulties, the script not getting handed in on time, etc, how about because it's just rubbish?

What do you do if you're Big Finish and the story is an absolute heap of sh*te? I mean terrifyingly, Timelash/Twin Dilemma bad. On TV, there are these people called script editors who take the scripts writers produce and, if necessary, make them palatable. But if Big Finish edits a really bad script that never got passed by a script editor, is it the authentic production fans wanted? If they don't, aren't they going to be making an absolute heap of Timelash sh*te?

The route Big Finish chose with Mission To Magnus, Philip Martin's lost script from Colin Baker's aborted second season, was not to edit the script. Oh dear.

Now Mission To Magnus has everything: it has the Doctor's school bully; it has a planet ruled by women facing war with a planet ruled by men; it has Sil from Vengeance on Varos, who has a consignment of winter woolies (his words, not mine) to sell; it has child actors.

In short, it's an absolute heap of sh*te. Normally, I don't endorse Third Reich policies, but if you can, please burn any copies of this play that you come across. Please.

We've had the past, which tried to be Monty Python and failed, but wasn't bad when it was serious; then we had the present, which was pretty good apart from a few dodgy performances and odd directorial choices.

Now we have the future. The story carries straight on from the previous one again, except the Doctor and Nyssa appear to have ended up in some futuristic tourist park populated by Northerners and aliens, including Lisa Tarbuck and Keith Barron.

Except, as the title of the story and the cover should tell you, things aren't what they appear to be.

So it is with An Earthly Child, a potentially very good idea, which is already available to pre-order, having been sent to subscribers in December. In it, Paul McGann journeys to the now defunct future in which the Daleks mined out the Earth's core to turn it into a spaceship, so he can visit Susan, his granddaughter.

Yes, the Doctor not only has kids, a wife and probably a mum, he also had a granddaughter – the very first companion to the very first Doctor, William Hartnell, in the very first story, An Unearthly Child (which you can watch all of on YouTube). Played by Carole Anne Ford, she stayed behind on Earth to help rebuild the planet and married a man called David Campbell.

Ford is back as Susan for this story, set 30 years after the invasion, and she's accompanied by Paul McGann's son, Jake McGann, who appropriately enough plays Susan's son, Alex – the Doctor's great-grandson.

Episode one, The Castle of Fear, ended on a cliffhanger and episode two, The Eternal Summer, more or less carries right on – except it doesn't.

The Doctor wakes up in a boarding house in Stockbridge, all things right with the world, except he's not sure how he got there or where Nyssa is. How did he escape that cliffhanger? And who will be the bad guy this time?

But for now, we have the Stockbridge trilogy. This sees the Fifth Doctor and Nyssa deal with events in Stockbridge's past, present and future. Apparently, Stockbridge was big back in the DWM comic strip of the 1980s (I missed it somehow), so this kind of follows on. Joy.

Here, though, before we get ahead of ourselves, we have the fifth Doctor and Nyssa turn up in Stockbridge, 1899, to watch a mummers' play. Despite being handed down word-for-word since the middle ages, somehow the Doctor, an Earl of Space and a Lord of Time, is included in the play's storyline. How did that happen? Best go back in time and find out, hey?

However, the biggest one-off clump of unmade Doctor Who stories came after the end of Colin Baker's first full season, when Michael Grade decided to 'rest' the show. Eighteen months later, it returned with the 14-part The Trial of a Time Lord and the original 'season 23', upon which production had already begun, never saw the light of day.

At least not on tele. Some of them were novelised by Target back in the 80s/90s, but now Big Finish has taken it upon itself to adapt some of these missing season 23 stories as full cast audios; it's also having a go at some other 'lost stories' from previous seasons in a new range of plays collectively called… well, have a guess.

The first of the range is The Nightmare Fair, former producer Graham Williams' first solo script. He was given the task of writing a story that reintroduced the First Doctor's whacky enemy, the Celestial Toymaker from (who'd have guessed it?) The Celestial Toymaker. To make things even easier, the story also had to be set in Blackpool.

Are you feeling the thrill yet?

So, there was obviously some anticipation as to how the final stories of the Charley/Sixth Doctor arc would play out and how she'd be written out of the series again. With the Sixth Doctor not knowing she would travel with him in the future, what would the cunning denouement be, we all wondered? Would she go without the issue being addressed? Would there be some clever bit of temporal mechanics? Would there be soul-baring and a frantic attempt to save the day?

We were all agog, since the Sixth Doctor/Charley pairing was actually very good. Ah, Charley: how we'll miss you, you were more or less the one thing that kept me listening to these, although given the groundswell of support for these reviews – thanks guys – I won't be quitting after this one and will be sticking with the main Whο range at Big Finish for the foreseeable future at least.

But after Patient Zero by Nick Briggs proved to be such a dud, hopes weren't high that there would be a great conclusion to the arc, particularly when Paper Cuts proved essentially to be Charley-free. Twats.

Now we're here, and Charley's off. How did they write her out, I hear you ask?

Bollocks. The exact same way they did in The Girl Who Never Was except not as well. Spoilers ahoy.

The reason I'm asking is that I'm rapidly running out of patience with them. There are far more misses than hits – which are only really relative hits – and they're actually quite painful to listen to.

I might stick around for the Missing Stories, purely to listen to Nicola Bryant (ah, Peri, etc, etc), but if no one's desperate to know whether these things are any good or not, I think I might give up on them once I've dispensed with the final Charley story (play number 126).

But on with Paper Cuts, a Sixth Doctor story by Marc "I never knowingly under-write" Platt set in (or rather near) the planet Draconia. If you cast your minds back to the years of Jon Pertwee, you may recall the Draconians, a reptilian race reminiscent of feudal Japan who appeared for all of one story.

Well, now they're back, Colin Baker's here to help them. Unfortunately, the Emperor is dead, and Charley isn't quite herself.

Look at that. Look at that cover. The best cliffhanger in the whole bloody thing and it's on the front bloody cover.

Sigh.

Anyway, moving on, this play marks the return of lots of things. It marks the return of the Sixth Doctor and Charley after months of Sylvester McCoy. It's important to note this is the beginning of the end for Charley since she'll be off soon which is a bit of a shame.

It's also the return of the Viyrans. What do you mean you don't remember the Viyrans? But Big Finish has been promising for simply ages that they were going to be a big series and they were going to tack Viyran stories on the end of all the plays in the run up to the release of this story. Don't you remember? Well, no, because they didn't and all we got was that one-parter tacked on the end of Mind's Eye about two years ago.

It's also the return of Nick Briggs as the voice of the Daleks, something that again is so important it deserves to be a "with NICHOLAS BRIGGS as THE DALEKS" on the front cover.

More than that, it's also the return of Nick Briggs as a writer and as a director. So writer/director and voice artiste on this one - anyone want to guess whether it's going to be a rigorously edited story that's been revised multiple times to make it the best play possible?

To take a leaf from Big Finish's book, I'm going to ruin the guessing for you and stick the answer on the front cover: no, it's rubbish.