Rona Munro hasn’t had the greatest luck writing for Doctor Who.  Her first serial, 1989’s cats-on-horseback adventure ‘Survival’ brought the curtain down on the ‘classic’ Doctor Who series and when she returned to ‘the new series’ in 2017 – having carved out an impressive reputation as a theatre and film screenplay writer in the interim period – her sophomore effort ‘Eaters of Light’ for Peter Capaldi’s final series became the lowest-rated episode of the series since its return in 2005. (Yes, we know that subsequent episodes have rated lower but the terrestrial TV ratings landscape has changed dramatically even in the last five years so let’s not get into all that…) A rewatch of the episode reveals a slightly mundane story with some interesting ideas not fully exploited in the 45-minute format. Munro now gets the chance to tell her tale properly in this new BBC Books/Target paperback and suddenly Eaters of Light fulfils its potential and becomes the story we suspect the writer always hoped it would be.

The Doctor and his companion Bill Potts have been arguing over the fate of the ‘lost’ Roman Ninth Legion, which mysteriously disappeared off the face of the Earth during an incursion into the wilds of Pictish Scotland in the second century. The Doctor lands the TARDIS in the forbidding Scottish landscape and, with reluctant comedy fellow traveller Nardole (played on TV by Matt Lucas) trailing in their wake in his slippers, he and Bill set off to find out the truth once and for all. What they discover, inevitably, is a hideous and hostile alien entity that has forced its way through a gateway between dimensions and devoured everything in its path – even the light of the sun – along with a group of baffled and terrified young Pict warriors and the teenage survivors of the Ninth Legion. The Doctor realises that if the gateway opens again, a huge swarm of the ‘eaters of light’ will flood through and wipe out all light and life on the planet…

‘Eaters of Light’ is easily the most literary of this new batch of Target adaptations. Munro’s text broadly follows the line of the episode ‘as seen on TV’ but she’s dumped some clumsy dialogue, tightened the narrative and, most significantly, added great wedges of background to the lives and hopes and fears of its young Legionnaires and  Picts, particularly young Kar who is tasked with protecting the gateway and holding back the creature when it occasionally breaches the portal between dimensions. It’s well-written, sympathetic stuff, adding colour and dimension to characters that come across as flat and unconvincing on screen. The story’s greatest problem though is the one that tended to bedevil the whole Capaldi era; the Doctor is an insufferable, unlikable arse. He’s rude, arrogant, patronising, condescending,  impatient and thoroughly bad company. It’s hard to root for the character in an incarnation that’s so tirelessly grumpy and intolerant. A couple of previous Doctors had a tendency towards the snappy – William Hartnell’s First Doctor and Colin Baker’s Sixth – but the Twelfth takes it to such extremes that it’s hard to believe anyone would want to even know him much less travel across Space and Time with him. His sulky, childish petulance at the end of the story when he initially refuses to admit that he was wrong just makes him an even colder fish. After the ebullience and joie de vivre of David Tennant’s tenth Doctor and Matt Smith’s hyperactive eleventh, it’s entirely understandable that the show needed to ring the changes and try something different but history has shown that turning your lead character into a surly, sullen, sarcastic and largely joyless misery probably isn’t the way to do it.

So whilst Eaters of Light isn’t able to rehabilitate a deeply flawed interpretation of the Doctor it certainly turns an eminently forgettable TV episode into something more thoughtful, more emotional, more terrifying and, ultimately, far more satisfying.

DOCTOR WHO – THE EATERS OF LIGHT is out now.