As supporting actor and executive producer, Mark Rylance generously supplies some valuable ballast and substance to an interesting, but underdeveloped and underimagined debut work from writer-director Fridtjof Ryder. It’s an atmospheric mood piece set in and around the Forest of Dean which doesn’t quite deliver either as psychological drama or folk horror, and might have been better boiled down to a short film.

Rory Alexander plays a troubled young man who has just been let out of a psychiatric facility after what appears to be a breakdown caused by the disappearance of his mother some years before. There are some disturbing dream-setpieces in the woods (perhaps the one this man sees at night) featuring a woman and a little boy.

Once released, he goes to stay with a garage mechanic called Dunleavy, played by Rylance, an amiably bleary, dishevelled but worldly-wise individual who was once a friend of his mum’s, or maybe more than a friend. Dunleavy lets him crash at his place, although the young man insists on sleeping in the car outside the house, and Dunleavy gets him a job at the garage where the other workers invite him out for a drink at an oddly conceived quasi-Lynchian bar; here the young man has a connection with a sex worker who reminds him of his lost mother.

The relaxed confidence and style of Rylance’s performance rather exposes the callow and uncertain nature of the others, while the direction, casting and line-readings sometimes seem a bit unconvincing. But set against this is the fact that Ryder is still only in his early 20s and is still clearly a remarkable potential talent. Inland points the way to more mature work still to come.

• Inland is released on 16 June in UK cinemas.