As he demonstrated in The Curious Incident of the Dog in the Night-Time, a canine murder mystery from the point of view of an autistic boy, former children's book author and illustrator Mark Haddon has a gift for reaching inside the inner world of characters whose minds should prove difficult to penetrate.

A Spot of Bother is Haddon's second novel aimed at adults, and again he writes his characters with great affection despite the fact that they're deeply flawed. Or, in the case of Bother's protagonist, George Hall, deeply insane.

The Halls are a family of people preoccupied with their own problems, largely centred around preparations for a backyard wedding. His daughter, Katie, is marrying a man no one, including Katie, thinks is good enough for her. Wife Jean is having an affair with one of George's former colleagues and struggling to plan the on-again, off-again wedding of her stubborn daughter. Son Jamie's reluctance to invite his boyfriend to Katie's wedding destroys that seemingly stable relationship.

Poor George finds his family falling apart and lacks the emotional tools to deal with the chaos head on. "Talking was, in George's opinion, overrated… The secret of contentment, George felt, lay in ignoring many things completely."

Newly retired George's own issues are an extreme example of the fretting the rest of his family – in fact, the rest of the world – exhibits. When he discovers a lesion on his hip, he leaps to the conclusion of cancer, and contemplates suicide. He gets caught up in the details of the how, discarding each method, including getting blind drunk and crashing the car – because what if he encountered another car?

"What if he killed them, paralyzed himself, and died of cancer in a wheelchair in prison?" George wonders.

The whimsical humour of the escalating hyperbole reveals a man who ponders the worst case scenario to an amusingly absurd degree. As the novel progresses, however, it becomes clear that this is no momentary flight of imagination or coping mechanism. George's insanity often escalates his worries beyond the point of reason.

The novel follows George's almost-logical reasoning. The spot could be more than eczema. The doctor didn't express himself with perfect certainty. He'd misdiagnosed Katie once. But George takes it several steps beyond reason.

Haddon doesn't inflict George with the cute insanity some fiction falls into, but the true-to-life confusion of being and dealing with someone who can seem no more odd than the average person on occasion, then lapses into genuine, over-the-top insanity.

A Spot of Bother is an often sweet, often heartbreaking story of a family falling apart and coming together. It's a deceptively funny, easy read with genuine poignancy. These compelling characters fumble their way through mental illness in the family the same way they fumble through their romantic relationships – sincerely, humorously, and ineptly.