This is a family in crisis. Gretta has done all she can to instill Irishness in her children - baked them traditional soda bread, taken them to Irish dancing classes, insisted on regular mass and communion - but they have gone their own way despite her and made a mess of their lives. Michael Francis married young and his wife is now too busy rediscovering herself to want much to do with him. Monica has ended up an unhappy, lonely stepmother trapped in the countryside. Difficult, dyslexic Aoife has run away to New York. All seem destined for further disaster.
In the oppressive heat they gather at their childhood home to search their father's belongings for a clue to his whereabouts.
Farrell's characters are all finely drawn but it is Gretta who gets most of the colour. With a noisy tendency to melodrama and a fierce passion for religion and family, she is the largest presence in the novel. Eventually, it becomes apparent she knows more about the events behind her husband's disappearance than she wants to let on.
This novel is all about the gradual building of its characters and since O'Farrell is an acute observer of people, insightful and emotionally intelligent, there is no faulting it on that score. Yet the story failed to engage me as much as I wanted it to - paling in comparison to her 2006 best-seller, The Vanishing Act Of Esme Lennox - and I finished it feeling vaguely unsatisfied despite every loose end being tied up neatly as can be.
Perhaps the issue is that the mystery is kept mostly offstage rather than being played out at the story's centre. Maybe all that dysfunction and angst just got to me.
O'Farrell is a writer with experience and flair. Her Riordans are skilfully created and entirely believable as a family and I suspect that's the real problem. Dominated by their mother, passive, self-obsessed and really quite whingey, if they really did exist I'm not sure I'd want to spend time with any of them - not even Aoife the outspoken rebel.
Instructions For A Heatwave is a convincing slice of life. On the whole it is well-written, structured and detailed.
Yet for me that extra something special found in her previous books is missing from this one.