Writer Richard Beard had a friend, Dru, with whom he used to go hill-walking and camping every year: an engineer on a ferry, a motorbiker, a real ale drinker. They did ‘manly’, outdoorsy things together, away from their wives and girlfriends and children. One day in 2001, Dru, then 43 years old, turned up wearing pink pearl earrings and with a request for her friend: ‘‘From now on, I want you to think of me as she.”

This beautifully written and thoroughly well-researched book is Beard’s searingly honest attempt to understand what his friend had gone through to arrive at this momentous and (to him at least) astonishing decision.

They agree to go walking across Wales together again a few months after Dru’s surgery. Along the way, Beard attempts to put the pieces together about Dru’s past life in the body of a boy and a man. This is no ghost-written autobiography, however; this book is as much about Beard himself as it is about Drusilla.

It is deliciously un-PC, unpreachy, refreshingly free of sentimentality, and, at times, drily comic. Beard’s admirable choice to be as forensically probing about his own feelings and thoughts as he demands of his subject, gives voice to what so many people think – but dare not say out loud – about transsexual people. Not the knee-jerk sensationalism of the tabloids, but the quiet internal gnawing anxiety that is an often authentic response to when our gender conditioning is challenged, because we know so little about transsexualism.

He admits, at the beginning, to wondering: ‘‘Is it catching?’’ He sets out to discover if Dru is real or if she’s some kind of trick or joke. What’s funnier than a bloke in a dress?

He speculates about all the possible motives that might make someone claim to be transsexual, which is, perhaps uniquely, a condition that requires self-diagnosis. ‘‘Isn’t changing sex, by definition, a superficial act?” he wonders.

Travelling with Dru, he admits to feelings of sourness, prickly suspicion, embarrassment, exasperation and, at times, fear of the way she looks. In a crowded pub along the way, he agonises; he wants her to pass, to fade away, to fade out, to be silent.

He realises his own sense of manhood hinges on what sort of woman he accompanies in public and is dismayed at what he learns about himself and about his own masculinity. He doesn’t want to be seen out with ‘‘that kind of woman’’.

He realises, endearingly, that he’s sexist.‘‘On a bad day’’, he writes, ‘‘transsexual women look so awful they’re embarrassing, if only they’d go away. On a good day, transsexual women look so convincing, they’re dangerous – they might trick us – if only they’d go away.” He makes the point that most autobiographies of transsexual people (transsexual is an adjective, Dru reminds him) are written by that peculiar species of human being, the writer, with that peculiar combination of narcissism and exhibitionism that sets us aside.

Those that catch the public eye, like Nadia in Big Brother, are driven by more than a need to change sex; they wish also to draw attention to themselves, a form of validation through celebrity; a dubious enterprise, to say the least, and one which distorts our understanding of the psychology of it all.

Beard’s search for a past life of tortured and suppressed effeminacy in his friend fails. He realises that there’s no major truth out there, no clearly defined three or four-act episodic structure upon which to hang a tale. There is no exotic revelation, no dramatic denouement; but in this tender biography, it would have been completely inappropriate.

There are too many jewels of insight along the way to dismiss this as an unexciting or mundane journey, however. Dru’s femininity, he concludes, is no more or less a mystery than anyone else’s.

This book’ s genius is to tackle the life of Drusilla Marland and give us a sense of her lived experience, her ordinariness as a woman, born in a particular time, under a particular set of circumstances, in a particular culture; he gently portrays her inconsistencies and foibles, her talents and weaknesses, her courage and nobility – in other words, her humanity.

But it is only achieved by Beard’s own willingness to deconstruct everything he knew about himself, as a man. Beard’s graceful admission of love and humility, at the end of this gentle tribute is touching and life-affirming. This book left me marvelling about human nature. There aren’t many of those kinds of books about.

Becoming Drusilla: One Life, Two Friends, Three Genders. By Richard Beard, Harvill Secker, €16.50

Dru Marland’s blog is here.

This review first appeared in the Sunday Business Post on 1st June 2008.