A triumph of masterly, nuanced performances

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

Is it a bad sign if a reviewer gets home to find mostly blank pages in the notebook?

In the case of Evolution Theatre Company's opening night production of Proof the answer is no; au contraire, even.

The cast of four have created such strong, clearly-defined characters, it is impossible not to be as engaged with the story as the actors.

What notes there are are mostly gibberish — possibly not unlike the screeds of nonsense written by Robert (Hugo McGuinness), a mathematical genius and professor at the University of Chicago who lives with a degenerative mental condition. His sole care-giver Catherine (Danielle Siata) has inherited much of her father's mathematical genius but fears she might also be prone to mental illness.

McGuinness plays not only the doting father, dependent on his daughter but through two flashbacks we see him first as the avuncular mathematics mentor to Andrew Stevens' geeky undergraduate and later in tragic decline. McGuinness seems to effortlessly plumb the poignancy in these changes.

In the opening scene he is the dowdily dressed, conservative dad who wishes his daughter a happy birthday.

There is an almost otherworldly character to the encounter. It is past midnight and depressed and dissolute Catherine is sitting on the deck and drinking champagne from the bottle in a less than celebratory manner. In a moment that is more of an unexpected turn of the card than a twist in the tale the scene calls into question her mental state and sets up the tone of the play.

Slopping about in track pants and sleeping until noon, Catherine is disaffected and apparently indifferent but Siata finds nuances in her character that are so masterly it's impossible not to laugh along with her subtly-played cynicism.

The play's plot hinges on the discovery of a game-changing mathematical proof and the question of its authorship but you'll have to see the show to find out what that's about.

Despite the play's deeper themes of mental illness and trust, Proof pops with humour and has a surprisingly warm heart. As one of Robert's last PhD students, Andrew Stevens' character Harold (Hal) Dobbs idolises Robert and is determined to sift through the professor's mountain of compulsive scribblings in case something of note is to be found for the greater good.

Stevens digs deep to find his inner American dweeb and plays him endearingly aware of his dorkiness.

When we see in a flashback Stevens as a younger student in awe of Robert he is awkward, shy and wears clean sneakers and a baseball cap the right way round. The transformation is remarkable.

As Catherine's cosmopolitan but crowdy sister Claire, Susan Partington runs on New York time and she knows someone in New York who might be able to help her sister. Partington's performance too is limned with nuance.

Her Claire is both concerned and cartoonishly (in a good way) comic.

Given most, if not all, of these actors have played larger-than-life characters in musical theatre, their ability under Dinna Myers direction to pull all that back, create finely nuanced characters, find rhythms in the dialogue that enable subtle but captivating emotional shifts and to remain connected with one another throughout is the stuff of the professional stage.

The warmth and intelligence of this show will stay with you long after the curtain call.

■ Evolution Theatre's production of David Auburn's Pulitzer Prize-winning play Proof runs until September 24. Tickets are available from Gisborne i-Site or . A dollar from every ticket sold will go to support people living with dementia in Gisborne.