Maple Giant Theatre’s last production in Oxford was the New York musical The Last Five Years, an emotionally aching tale of a relationship told through a wonderfully fractured narrative. Their new production is also highly emotive, and at times, difficult to watch. Also, it’s even better than their previous, excellent, production.

When David Auburn's Proof hit the West End a few years ago, it attracted some rave reviews, and it’s not hard to see why. Catherine (played by Amy Cooke-Hodgson) is one of two daughters left behind by the late, great reclusive Chicago mathematics genius Robert (David Thurston). She has been looking after her increasingly mentally ill father for five years, sacrificing her education and her own, perhaps quite special, mathematical skills. However, his death leaves her depressed and alone, and as her sister (Amy Enticknap) returns from New York to attend the funeral, she feels it is time to face her own past, so she can finally move out of her father’s shadow.

This is essentially a play about family dynamics, and it raises some tough, provocative questions among the equations and logarithms. It problematises the question of caring for a family member, for one thing, and it also deals with the spectre of hereditary mental illness and the effect it has on relationships within a family. The production handles these issues sensitively, and all the actors perform the roles with grace and class. They include Tom Wilkinson (pictured) as Robert's student Hal.

My main criticism with this version would be to do with the direction, which occasionally seems a little stilted. The cast spend a lot of their time emoting while sitting down or simply standing on the spot; there could be some more fluidity. There is, however, some effective, and unshowy, use of lighting throughout.

Certainly preferable to watching the recent film adaptation, this production of Proof catches the play’s subtlety and sensitive brilliance. It also marks another gold star on Maple Giant Theatre’s increasingly impressive record. It continues until tomorrow.