Simon Stephens prides himself on being a chronicler of the mundane. Which other playwright would set a play in unfashionable city satellites like Uxbridge and Stockport, let alone both in the same play?
This is a high risk way of working, since, unless one is careful, the mundane can become very boring. With the assistance of director Marianne Elliott and actress Lesley Sharp who is on stage throughout, Stephens just about pulls it off.
Miss Sharp plays Harper Regan, an ordinary woman suffering a midlife crisis through which we follow her for around 2¼ hours at the end of which, much against the odds, the play named after her ends on a note of hope.
For the vast majority of this time, we watch disjointed fragments of life, each with a different partner who helps to illuminate what it is to be this average woman.
Her odious boss mercilessly overworks his put-upon PA, flatly refusing a day off, even though it is to visit her dying father. After an encounter with a teenager that she has been gently stalking, Harper has a caring meeting with the family.
Nick Sidi as husband Seth is an architect who is apparently out of work, while 17 year old Sarah, a convictionless Goth impressively played by professional debutante Jessica Raine who is still at drama school, studies hard but still seems to be struggling to settle in London two years after the family's relocation from Manchester.
Harper then goes AWOL, in a vain attempt to tell her dying father how much she loves him. In Stockport, she has a series of bizarre encounters with a sympathetic nurse, a drunken, lecherous journalist (surely no such character exists in real life!) and then a one afternoon stand picked up on the Internet.
This all leads to two crucial revelations that validate and reassess all that has gone before. In particular, the discovery that Seth is on the sex offenders register as a convicted paedophile explains why his poor, loyal wife is constantly stressed and won't risk leaving her dead end job and creepy boss.
Harper returns having caught the unusually contagious disease of truth-telling from her unloved mum, Susan Brown. This puts strain on the whole family but makes them face life and their own evasions in a way that might ultimately be positive.
Hildegard Bechtler has created an unusual but very clever compartmentalised, minimalist set based on a revolve, designed to symbolise the confusions in Harper's mind.
Of itself, each individual scene is mildly witty, quietly unexpected or depressingly shocking. Together, they build up into something far greater.
The evening is carried on the shoulders of the excellent Lesley Sharp who makes you really care about the central character and is supported by a series of good cameos from a cast of talented character actors.
By looking at life today through the eyes of one ordinary woman, Simon Stephens uncovers the complexity of our relationships with family, employer and those whom one casually encounters for no real reason.
This type of low key theatre will not be to everyone's taste but many will find themselves nodding in recognition and identifying these characters from people that they meet every day.