There are times during Josephine Decker’s bold film that she appears intent on taking the mickey out of the acting profession, as much as she is on exploring the devilishly active mind of Madeline (Helena Howard). Such are the bizarre things that they do in the name of improvisational acting.

The story concerns Madeline a very bright individual who to get away from a troubled home life, is a member of an immersive improvisory theatre group run by Evangeline (Molly Parker).

It’s a place that Madeline can escape to and let her imagination rip. Through the groups exercises and disciplines Madeline’s personality and problems come to the fore. Picking up on this Evangeline slowly starts to pull out Madeline’s story and sculpt her production around it.

At the same time Madeline is going through the usual teen experimentations of booze and porn. As demonstrated during a party at Evangeline’s with her family and friends when Madeline totally loses it after hitting the bottle.

There’s also the issue of Madeline’s mental health which is fragile, though more alluded to than overt. Though not so fragile that she has lost her wits as twice she uses the improvisational course and technique to attack Evangeline and later her own mother Regina (Miranda July), the latter with Evangeline so wrapped in the performance (and her own ego) that she doesn’t notice Regina’s quite obvious distress.

They are genuinely disturbing scenes but focus in on what a find Helena Howard is. Her shifts from wayward daughter, social misfit to manipulative cruelty with nary a shrug are astonishing. Though in no way upstaged are Parker and July with the former almost trying to displace the other.

It is beautifully filmed without any doubt with clever use of refection, colour and shadow. But as lyrical and deft as it is it does wear especially towards the end as Decker seemingly lets the troupe loose to improvise at will and it just becomes overwhelming and trying, to be generous.

Nevertheless this is an interesting film that for all its astute technical prowess does have a vibrant heart and an emotional centre.