Mavis Gary is an emotionally stunted train wreck who authors (a word she stresses whenever someone calls her a writer) a dying series of young adult fiction. But she’s not actually the creator of the series. She’s the ghostwriter. Little departures like this create a realistic curve within the shockingly inspired Young Adult, the new comedy-drama staring both Charlize Theoron and midlife delusions.

One look at her and you’ll know that Mavis is a spiteful, pitiless creature, perpetually stuck between nostalgia and an unbending adherence to her own self-importance. She is a prom-queen whose princess complex never left. She is a cruel, unsentimental and borderline alcoholic, perfected in earnest imperfection by the triumphant writing of Diablo Cody and Jason Reitman (the duo, whose previous credit was Juno).

We begin at her frowzy apartment in Minneapolis, which she shares with a little dog and a television set. She’s on a deadline to finish the last of the series of novels, brought down by bad sales. And so, we see her sopping up scrupulous amount of Coke (as if water never existed), jotting down half-hearted paragraphs, and picking up hip-slangs from teens working at department stores.

Mavis’ distraction isn’t simply a case of writer’s block. She’s upset because her ex-beau (Patrick Wilson), who lives in the suburban town of Mercury, just had a baby. And now she wants him back – or at the very least liberate him from the shackles of homebound life, a facet he himself doesn’t realise, because it simply does not exist.

Theoron powers up a natural multi-layered, Oscar-worthy presence during the film’s magnetic 90-minute running time. She’s given brilliant support by Patton Oswalt’s Matt – a geeky reminder of high-school violence, who works as the bookkeeper at a local bar. Matt isn’t as much a romantic pit stop as a small bump in the road, a facet Mavis shockingly makes clear near the film’s climax.

Shot in 30 days with a miniscule budget of $12 million, the low-key drama may feel like a rough first draft, which fixates on Mavis’ personal delusions, and ultimately her humiliation. A detached look and some pondering reveal otherwise.

If Young Adult sounds like a run-of-the-mill romantic-comedy, then banish the thought. It is Sundance Festival all the way. Released by Paramount, the film is rated R for stark, biting humour and nudity. — Mohammad Kamran Jawaid