"Take my hand."

No longer able to live in our universe, the Doctor has taken his battered TARDIS into the divergent universe. He has no idea what he will find there, though the last person he expected to find aboard his ship now is Charley.

When the TARDIS breaks up, the two friends are cast out into a stark, white void. Unable to decide on another course of action, they start walking.

As circumstances force the Doctor and Charley to confront their feelings for each other, they begin to suspect that someone, or something, is guiding their reactions. Are they truly alone in the white void?

Scherzo is not an easy play to review. There is no guest cast to either praise or condemn, no well or badly realised historical/futuristic world of the author's imagination to comment upon. Just the two leads stuck in an unending white void.

Paul McGann and India Fisher have worked wonderfully well together since day one and we now come to expect top drawer performances from them as a matter of course. But given a two-hander to work with, knowing they are carrying the whole story themselves, they raise their game that little bit more, running through a bewildering sequence of emotions with aplomb.

I feel I must comment at this point on the fact that this is the third 8th Doctor tale in a row where the relationship of the Doctor and Charley has been pivotal to the plot. While McGann and Fisher have proved themselves up to the challenge each time, I think it is time this plot point was given a rest for a while. It is in danger of becoming as stale as Ace's teen angst.

There isn't much really I can say about the plot. In the hands of an author less gifted than Rob Shearman, it could have been a complete mess. And while it is at times confusing and repetitive, this is a bold experiment and worthy of our praise for that alone.

Zagreus was a bit of a pantomime. It had a fantastic setup with one of the best cliffhangers ever in Neverland, but when it came down to it was a bit of a muddle. Still, as far as the average anniversary story goes this "romp" was still leagues ahead of the competition.

However it sets up another series of Eighth Doctor adventures and once again in Doctor Who continuity all bets are off - the reset switch is pressed.

Scherzo delivers beautifully, coming as it does from Rob Shearman - the man behind The Chimes of Midnight and The Holy Terror - two of the best audios in the range. A two hander (there's a certain irony to that description too as you'll hear), it nevertheless manages to feel vast and scare the socks off you as you listen. In episodes two and three there are some moments of genuine horror, some twists which compell you utterly and some great "jump out of your skin" moments - this audio is one for headphones or a quiet room. Give yourself up to it and feel the sensory deprivation of the characters as audio becomes your only link to the world, and sound isn't always being truthful with you.

The lead performances are excellent, both characters struggling to make sense of where they are and what they're feeling. The developments in the relationship between the Doctor and Charley are addressed very well within the plot and without ever seeming awkward or gratuitous... The Doctor's character is a surprise here. He's in a new place, out of his element and stripped of what made him a superhero... all bets really are off.

With audios like this, and Chimes and Holy Terror were the same, there's often an anticlimax as the events resolve themself. When there's such a mystery established it's almost impossible to narrow down the explanations without feeling like we're losing the thrill of the questions. The resolution here doesn't disappoint - it's strong, dramatic and sets up the rest of the series beautifully.

Scherzo is great - a cracking good audio character piece, using the audio medium to its full potential.