Dominic Mitchell's script was plump with allegorical meaning, but has this sensitive take on a violent genre fulfilled its promise?

In the Flesh arrived on BBC3 heavy with promise. Here was a drama set to push the zombie genre into uncharted territory and turn the tables on our preconceptions. Pushing genres and turning tables is just what it did, too, or rather, would have done if its appealingly wispy lead Kieren (Luke Newberry) had the upper body strength.

18-year-old PDS (Partially Deceased Syndrome) sufferer Kieren Walker was no robust brain-muncher, but a guilt-ridden teen with more to bear on his slender shoulders than the angst of being an arty misfit in a small town. In his untreated feral state, he had murdered neighbours and chowed down on the contents of their heads. Post-medication, the grisly contents of his own head spilled out into traumatic flashbacks that haunted his fraught homecoming.

In the Flesh was 2013's riposte to the macho monopoly on screen zombies. Yes, enough shotguns were fired in the course of its three episodes to keep the NRA grinning, but its politics were liberal, and its lead a sympathetic counterpoint to every blank video-game or movie zombie you've seen turned into a bloody wall streak by a hurrahing hero. With one humanising contact lens in and one out, anaemic revenant Kieren looked like a watercolour painting of a teen David Bowie. His washed-out sylph was the first TV zombie you wanted to hug, cook a shepherd's pie for and help to write his Ucas personal statement.

"I was a teenage zombie," that statement might begin, "but I'm better now." Or, to adopt In the Flesh's satirical take on the language of treatment, "I'm working through it."

Cheek by jowl with channel-mates Snog, Marry, Avoid? and Don't Just Stand There… I'm Having Your Baby, In the Flesh's serious, empathetic reversal of a classically fun, guts'n'gore genre made it a misfit in its own home. Its Ken Loach-meets-Paul Abbott landscapes, desaturated colour and gently assured direction set it apart from the fast-moving, pop-riff style of other programmes sporting BBC3's neon pink logo.

As a story of prejudice, grief and a string of other abstract nouns, Dominic Mitchell's script was plump with allegorical meaning and much less interested in the z-word than some TV listings would have you believe. The story was an anti-suicide tract and a fable about acceptance before it was ever a zombie tale, closer in its first episode to 2007 rehabilitation drama Boy A than anything by George Romero.

Its mutable symbolism – Kieren and his undead pals stood in for any number of states of "otherness" – was both masterstroke and over-egged weak-link. If PDS-sufferers mean everything, do they actually mean anything? Underneath the metaphors, was In the Flesh more than a melodramatic lesson about tolerance and loving thy neighbour?

Perhaps not, but it's a lesson that bears repeating. Debating the potency of symbolism in a teen-targeted BBC3 drama is a welcome pinch-yourself moment at a time when youth programming doesn't always celebrate the cerebral.

In the Flesh's writer has said that there are more ideas in the wings, but can its allegorical premise sustain another trip to rural Roarton? The dramatic potential of Kieren's return may be exhausted, but there are doubtless other stories for this likable cast to tell. Were it to return, fingers crossed it would be with a few more shades of dark and light in the supporting characters.

More interesting will be its aftermath. Mitchell came to the BBC's attention via a Writersroom scheme, proving that gambles on new talent do pay off. With Channel 4 set to air French drama Rebound (Les Revenants) in the coming months, the amicable zombie twist is just getting started.

Louisa Mellor is the TV editor of denofgeek.com