Remember 1984 and the first news items filtering through of a famous Auckland playwright abducted by feminists and tied to a tree with the word "rapist" around his neck?

It became known as the Mervyn Thompson Affair, and so quickly does the present become the past that, less than 20 years later, Stephanie Johnson has been able - hilariously, hideously - to use that incident to show us something of the way we were. As one of her characters remarks towards the end of the novel: "What you did that night, it was a sign of the times, of the 80s. It would never happen now."

The 1980s, we uncomfortably remember, was the period when "isms" and "ists" bit hard into our framework. Racists, sexists, classists (and lookists, as one of Johnson's feminist hisses) were stridently derided on the Left which, post-1981, was splintering into a number of anti-ism groups. Now, we often use these terms ironically. Then, they were in deadly earnest, as we see.

Johnson offers us a satire on those days, and you've got to admire her guts: she explores this recent history with the courage usually reserved for events much further in the past. Can we really set aside our lingering received wisdoms and have a good laugh at ourselves?

Howard Shag is a New Zealand icon: an ex-All Black and writer of best-selling trash, he nevertheless has a secret that the times demand he keep to himself. Unfortunately, some local wimmin believe him guilty of rape and take summary action against him. From that sorry episode stretch a number of consequences, reaching into the lives of characters who initially seem unconnected but who are gradually woven into the same story.

There is Jasper, a kind of protege of Shag's who is now awaiting trial in a Sydney jail for drug trafficking and child pornography; Franca, a slick Sydney psychiatrist who studies suicide not, as her grandmother would like, "the happy and the kind"; Jasper's mother Lena who embodies feminist extremism and, later, Waiheke wackiness; Richard, Jasper's estranged father, an unlikable, drunken journalist; and Melody, the sanest of the lot of them, a rugby fanatic who is writing Shag's biography.

Along the way, Johnson puts the boot (usually but not always with gleeful good humour) into anti-racists, anti-sexists, self-hating white liberals, New Agers (the Womb Burial and the naming ceremony are triumphs of excruciation), communes, psychiatrists, counsellors - anyone, in fact, who can be perceived as having adopted a one-size-fits-all lifestyle.

The 1980s was a blaming era, and most of Johnson's characters are preoccupied with blaming others for their own predicaments, or for real or perceived crimes. Everyone has bigoted ideas about everyone else, and yet in defiance of that, Johnson's characters themselves are many-sided. Not grey, but spotted in black and white: things you like, things you don't. Johnson plays games with our sympathies to show us how impossible it is to make judgments of others.

Do we, for instance, desire to rescue and nurture Jasper (as does Franca) because we see the hopelessness of his childhood (off his face at 8 years old, sidelined by his mother and rejected by her wimmin friends who allow only Maori boys inside their large Herne Bay house); or do we reel from him in horror at his adult crimes? At what point does the lost little boy become the brute? How do we see him then? Who should take responsibility for what he has become? Or for what he has not become, as he trails in his wake a list of could-have-beens: chemist, carver, good boy ...

These remain important questions and Johnson has given one of the best explorations I've seen in fiction of such pressing issues.

This isn't the Mervyn Thompson story - yet I can't help but feel that Johnson, who was a student of Thompson's, has written a worthy epigraph for him, one that will make people both laugh, and reassess the kind of thinking that led to his demise.

The predominant colours on the cover of The Shag Incident are blue and pink, the same shades litmus paper goes when it's dipped in fluid. What will show when this book is dipped into the well of our recent memories and sensitivities? Hopefully, that we've got the balls (a very unfeminist expression, that) to face our past, ridiculous as some of it is, and have a laugh at our own expense.

I really enjoyed this book. Its tension works well; it's marvellously complicated, wonderfully chilling and provides a feast of personalities. Johnson's writing is skilful, insightful, witty and she has a truly light touch. One of its enduring delights is rolling the story around in your head afterwards, going over the complicated relationships between the characters, and reminding yourself how it all tied together.

Foolish, drunken Richard, firmly on the skids and with no one to blame but himself, tells us at some point that "loose ends are a part of life", and of course he's got a point.

They're not part of Johnson's fiction, though, which if anything is just a little too polished and perfect, the many-stranded story just a bit too tweaked into shape. Of course, as readers that's what we want, or think we want: explanations, meetings (not missed connections), sharing of information, letters to be read and not simply screwed up, denouement, retribution ... Aha! If that's what we want, perhaps we're no better than that crowd of angry feminists.

But there is a little too much exoneration, niceness and tidiness at the end for my taste. The worst punishments are those meted out by people to themselves. Life moves on and passions, simply, fade.

Vintage $26.95