Equilibrium written by Matt Fitton and directed by Ken Bentley

What's it about: Still looking for a way out of E-Space, the TARDIS crashes to Isenfel - a realm of snow and ice. Snarling beasts stalk the frozen plains, a feisty princess leads the hunt, and a queen in an ice palace rules over her loyal subjects. But this is no fairytale kingdom, and everyone in Isenfel knows the price of survival. While Nyssa and Tegan uncover deadly secrets hidden in the palace, Turlough flees for his life across the tundra. And as for the Doctor... he only ever wants to change things for the better. But in a world such as Isenfel, such a hope may not even be possible.

An English Gentleman: 'You helped me carry on despite everything. You have no idea, do you? The effect you have. You upset the balance for the best. There's no equilibrium with you. You'll always tip the scales in everyone's favour but your own...' The Doctor is a firm believer that politeness gets you everywhere and reminds Tegan of that. He obviously decided to chuck that approach out of the window when he regenerated after seeing how far it got him in an increasingly hostile universe. Would describe the Doctor as curious or nosy? This is great scenario for the fifth Doctor to be trapped in because he is by far the nicest of the Doctors. To have him confront a society that is outwardly so civilised and yet assassinates their populace as a matter of law sees the character trapped in a conflict of respect over disgust. He's always been a firm moral compass and risen to the occasion (Enlightenment in particular) when he thinks that people are being treated unfairly. I wonder if the stuffiness and unchanging society of Isenfal reminds the Doctor of Gallifrey and why he left there. He is forced to confront the fact that he might be responsible for the death of this world and it weighs heavy on him. There is a beautiful moment between the Doctor and Nyssa in the last episode the likes of which we haven't heard since The Eleventh Tiger. The intimacy of their relationship is laid bare in an extremely emotive way that quite took my breath away, thanks to the sincerity of the writing and the performances. The universe is ultimately doomed but that doesn't stop him from trying.

Alien Orphan: Although she sounds remarkably patronising when she's lecturing Tegan, Nyssa is correct that they shouldn't bring their own standards to judge the society that they are visiting. And they certainly shouldn't try and change how things are just because they perceive them to be wrong. There is a conflict over this matter between the two girls that is gently explored throughout the tale and utilises them both to good dramatic effect. They bring change to every environment that they visit but is it always change for the better? A court of royalty and manners is precisely the sort of environment that Nyssa slips into comfortably. She understands how to behave here. In a gentle moment Nyssa admits it would have been wonderful to have Tegan around when she was nursing her children. She has a regal bearing and comes from noble stock but Nyssa firmly believes that it doesn't matter where you come from, only the wisdom you take from your parents. Wise beyond her years? Only because she is an old woman turned young.

Mouth on Legs: It looks like Fitton is going with the pioneering Tegan from the audios as opposed to the miserable old cow who was on the telly. Her suspicious nature seems to be out in force and despite appearances for once she is correct. As you might imagine Tegan isn't amazing with children, she isn't exactly known for her patience.

Over the Shoulder: The boy with the fiery crown? Thanks to JNT's insistence that there weren't too blonds in the series, Turlough is vividly depicted on audio. He is sarcastic when talking about Nyssa and Tegan, answering that he has done nothing to deserve such punishment when asked if he is promised to either of them. The last time Turlough was delivered a romantic subplot it descended into dreadful soap opera histrionics...I'm pleased to see it is handled far less earnestly this time around. He's a boy with urges and everybody recognises that. And he gets a good snog before the story is out.

Standout Performance: Annette Badland, let me count the ways I love thee. A revelation as Margaret Slitheen and the most convincing thing about the entire species, the saving grace of Wizards vs. Aliens which failed to live up to the promise of The Sarah Jane Adventures (aside from a handful of stories) and an actress that can even light up the dreariness of Albert Square. She gives a typically polished performance as Queen Karlina although I have to be honest it wasn't until episode three until I recognised her voice. Until that point I simply thought it was a very strong performance from an unknown actress. The Queen is so beautifully performed and characterised that I was quite moved by her scenes with Skarsguard in the last episode and her final decision.

Sparkling Dialogue: 'It's no mean feat to play an instrument whilst it melts.'

'Only a human life can balance a human life!'

'You did have the voice of God after all!'

'You can't make a bargain with entropy...'

'A kingdom consists of its people not it's land.'

Great Ideas: The Doctor compares their situation in E-Space to losing a hairpin in a swimming pool rather than an ocean (N-Space). When the choices are landing or crashing...then brace yourself for impact! It's quite a dynamic opening all told (despite some dreary technobabble) and one that drags you into the story with some urgency. The missing stabiliser at least gives a further reason for these stories to be linked which is the strongest purpose for a trilogy in quite some time. And the TARDIS being lost in the ocean is a good enough reason to plough forward with the story and isolate the regulars. It reminds me of a Hartnell adventure where separating them from the Ship was a weekly occurrence (Marco Polo in particular given the snowy setting from the outset). The work of all in Isenfal is to make the most of their environment of ice whilst maintaining its form. A vessel appeared from the stars and a man was found in the wreckage - Solus but he died on impact. All energies must be kept in harmony, including people. All arrivals are balanced by departures, every birth is balanced with a death. If the people don't ensure equilibrium then the planet takes care of it. A secret crèche, saving the lives of families that would have been culled. Fitton has thought through his idea of maintaining balance and carefully built a society with it, including resistance to the idea. The idea of a world just ending is an extremely powerful one, even if it is just a metaphorical notion. These people are lab rats but the laboratory has been abandoned and the experiment left running. This society is painted in vibrant enough colours that when the culling begins you genuinely feel something for those characters that are left behind. The universe of E-Space is collapsing and the rate of decay is much quicker than expected. By simulating the collapse they can discover more about their eventual fate. The resulting experiment is Isenfel. Once the Doctor triggers the shutdown of the experiment...he cannot stop it. I guess that will teach you to read the manual properly before pressing buttons.

Audio Landscape: Icy wastes are a staple of Big Finish and have been utilised to create a vivid environment on many occasions for a very good reason. They are remarkably atmospheric. Winter from the Adept, Lurkers at Sunlight's Edge, Snow Blind, Land of the Dead, Frostfire...with some expert sound effects you can chill the blood and create a picturesque scene. Explosions, alarms, a hissing TARDIS, snowy wastes with hushing winds, crunching through the snow, cracking ice, the TARDIS splashing into water, clomping hooves, footsteps, a ticking clock, bubbling pots, a sleeping beast, snarling, pounding feet, babies crying and gurgling, galloping horses, a coughing TARDIS, the kingdom crumbling, the statues falling.

Musical Cues: Fox and Yason usually means a treat for the ears and they do not disappoint. I particularly enjoyed the musical interludes that were genuine performances being put on for the Doctor and his friends, they helped to give the first episode a comforting feel.

Isn't it Odd: Having three companions doesn't have to be a hindrance as long as they all have something to do in a handful of plot threads...but I find their group scenes together troublesome because nobody gets the focus. They all slip into the background, all vying for attention. Maybe three is too many. Equilibrium does a good job of giving Nyssa, Tegan and Turlough all something to do but it struggles when they are all in a scene together with the Doctor.

Standout Scene: I was impressed by the first cliffhanger, a dramatic sting at the end of a gentle scene setting episode. It as almost starting to feel as if this was going to be a Doctor Who story without any peril (which would certainly be different) and when the danger emerges it turns out to be because of the regulars and not happening to them. Nicely done.

Result: 'That's the trouble when you are trapped inside the system, you can't see any other way...' There is an interesting idea at the heart of Equilibrium and Matt Fitton does a fine job of exploring it. If you are going to set a story in E-Space then this is precisely the way to do it on an enchanting new world the likes of which we have never seen before and handling engaging concepts that would make the mighty Bidmead proud. I don't mean this as a criticism of either writer but Fitton is turning out to be the next Eddie Robson, not the highest class of Big Finish writer but astonishingly reliable and always turning out something that is worth listening to. He has been responsible for a fair amount of the better material to emerge from a handful of audio ranges of late and whilst it does occur it is rare for him to have an off day. Equilibrium sees him focussed, delivering a polished script with plenty for everybody to do and a plot which develops in a pleasing and surprising manner. I good sign of a strong Big Finish story for me is my willingness to plough on and see the story through in one sitting and not break it up in two halves. I was having a great time with this and lost my evening of study that I had planned. Damn you, Fitton. I really like how this trilogy is developing too, with each of the stories linked in a robust manner and the overall story gaining some dramatic momentum as it progresses. This isn't top tier main range like last years The Widow's Assassin or Breaking Bubbles but it is certainly high class second tier and reminds me of stories such as Time Works and Brotherhood of the Daleks. Solid stories, fascinating to listen to, classically done Doctor Who that is almost entirely plot driven. Hell, it's worth listening to this story just to experience Tegan holding the baby: 8/10