After following the excellent Invaders From Mars and Chimes of Midnight, it might be suspected that Seasons of Fear wouldn't be up to the same standard. Not a bit of it!

The Doctor finally steers the TARDIS to Singapore on New Year's Eve 1930, so Charley can keep her appointment with Alex Grayle. But when the Doctor encounters his Grandfather Sebastian, things take a turn for the worse.

Sebastian Grayle claims to have killed the Doctor, to have recreated the world of Singapore 1930 with the help of his alien masters, who now rule the Earth. It is all one giant hoax, so he can finally gloat with the man who was his nemesis for so long. But as the Doctor doesn't remember ever meeting Grayle before, then how could all this be true?

Forced into a desperate chase through Earth's history, the Doctor and Charley must thwart Grayle and his 'masters', before human history as they know it is destroyed forever!

Seasons of Fear is certainly an ambitious tale, spanning four very different locations and times. But it is done with aplomb, with the regulars turning in their usual excellent performances and the guest cast seeming to enjoy the challenges set before them by writers Paul Cornell and Caroline Symcox.

Of the guest players special mention must go to Stephen Perring, who plays Sebastian Grayle throughout 1625 years of history. The subtle changes in performances depending on the circumstance and place in time are quiet wonderfully achieved.

Also of note are Grayle's alien masters. Without giving anything away, they are revealed to be an old enemy and a totally unexpected one at that. Despite the clues throughout the play (and they are there, with hindsight) I didn't guess their identity. Though this just might make me slow on the uptake! And they do work surprisingly well on audio.

And the cliff-hanger at the end of part four (yes, part four!) is just stunning! It sets up the rest of the season's ongoing arc nicely and is chillingly sinister into the bargain. This new season from Big Finish is certainly about time!

Seasons of Fear comes highly recommended, as the rest of the season so far has been. With three stories still to go, it remains to be seen if this level of quality can be maintained.