Lila Avilés's feature debut The Chambermaid (La Camarista) gives a voice to a member of the large invisible army who make society function. Using a muted, semi-documentary style, she follows the grinding daily routine of Mexico City maid Eve (a graceful, zen-like Gabriela Cartol). Eve is diligent and hard-working, clearing away the mess left by people who might share the city but who live in a completely different world.

The Chambermaid is a thoughtful window into the yawning gap between the 'haves' and 'have nots'. This young single mother has a lengthy journey to the place where she works. The luxury 5-star hotel is intentionally impersonal – a concrete and glass haven where the wealthy savour their privileges and exert their power. Eve is a necessary intruder from the real world – a ghostly figure whose presence is unseen and whose efforts are taken for granted.

Eve has ambitions of her own, seeing very different versions of who she might be or become in the rooms that she visits. Her greatest desire is to work her way up the ladder to the 42nd floor. She enrols in the hotel's adult education programme. Friendships develop, a flirtation with one of the hotel's window cleaners hints at the possibility of romance. Little moments fill in the details of Eve's stoical life.

Gradually, over the course of a quiet, rigorously unsentimental film, this ghostly figure comes into focus like a stranger emerging from the fog. By the end of a deliberately paced but engaging production, the enigmatic Eve has become flesh and blood. A woman with hopes and dreams, virtues and failings, she deserves to be seen no matter the odds against her. It is a tiny triumph in a film that marks out actor, theatre director and documentary maker Avilés as a talent to watch.

Limited release from Fri 26 Jul.