It would be difficult to underestimate Joy Division. In the realms of post-punk, in the era of new wave, their dour, monochromatic intensity was a beacon of pure black light. Influenced like so many others by the Sex Pistols, when they plugged in, for some reason this northern four-piece translated that often irrational fury into an even more nihilistic existential gloom.

When it all imploded they were on the verge of greatness: the acclaimed Closer LP and classic 'Love Will Tear Us Apart' single were about to hit the shelves, and a debut American tour booked. Real success seemed there for the taking when they traded it all in for the worst kind of immortality.

Maybe if they had survived Joy Division would even now be a chicken-in-a-basket cabaret act playing for middle-aged men in green Macs. They didn't. On the night of May 18 1980, tall, frighteningly charismatic singer Ian Curtis returned to his Macclesfield home facing divorce and apprehensive about the States. He watched Werner Herzog's Stroszek (about a man torn between two women who resolves his dilemma through suicide), took a picture of his baby daughter Natalie from the wall, and played The Idiot LP by his idol, Iggy Pop. Then he hung himself in the kitchen by the family clothesline.

Between Hendrix and Kurt Cobain, Ian Curtis was the most visible death in modern music. Rock deaths are nothing new, of course, but suicide is altogether a darker, stranger field. As Cobain showed, self-inflicted death leaves the audience confused and angry. Cobain, like Curtis, had serious medical problems, but unlike the Nirvana frontman, the text of the Curtis suicide note has never been made public; what he said to his wife of five years remains largely shrouded in mystery. Sometimes what she doesn't tell us is as telling as what she does.

Touching From A Distance is about Ian Curtis and the band Joy Division, told by the one person qualified to tell it. The book, as Deborah Curtis explains, is her attempt to lay to rest her late husband's ghost. As anyone who's seen his ferocious epileptic dancing on youth access show Something Else in 1979 will testify, Curtis was arguably the most exciting frontman to emerge from the maelstrom of punk. But even the man's most devoted admirers might find difficulty with the sacred cows slaughtered in these pages. As Deborah Curtis tells it, her husband was not a nice man.

This Ian Curtis was briefly a racist, Tory voter, inveterate and selfish chain smoker, and sometime reggae enthusiast with a death wish. (He took his first overdose at fifteen, and long said he wouldn't live beyond his early twenties.) But the man his wife knew was also generous to a fault, handsome and never malicious, even though before their marriage he was prodigiously jealous, and the subjugation elaborated in these pages - what she could do, what she should wear - is frightening. At their engagement party he threw a Bloody Mary over her for dancing with another man.

As the band became steadily more successful, the singer was boxed in by his own health and temperament: he was diagnosed as epileptic and put on medication that magnified his personality into an even more paranoid, unreasonable version of itself. He embarked on a messy affair with a Belgian woman, froze his wife out of the band's growing popularity and gradually left her behind in his ultimately self-destructive journey. It was she who eventually initiated the divorce.

Curtis was an enigma and this book will not change that. Questions have never really been answered about Joy Division's flirtation with fascist imagery (their first single cover; a name taken from the sections of Death Camps given over to Jewish brothels). And on a couple of occasions there are hints about the man's sexuality - he had a fondness for Manchester's gay pubs - so that when she finally confronts him, Deborah Curtis asks if his affair is with another man.

Reasons went to the grave with him - his good friend, guitarist Bernard Sumner blames the medication - but certainly Touching From A Distance (the title comes from the 'Transmission' single) is his widow putting the subject to bed. And a surprising, refreshing work it is too. Despite the occasional clumsy sentence, a few too many exclamation points, it's a bleak but clear-minded, unsentimental work. The chapter in which she describes finding his body is remarkable.

In his foreword, Jon Savage asks whether the things people found so alluring in the man were paradoxically the very ones that killed him. It's a chilling thought, and one bolstered by a comprehensive appendix of his lyrics. Ian Curtis took what bassist Peter Hook called "a permanent solution to a temporary problem", but what he left behind - listen to the mesmeric, posthumous Still LP - has ensured the man's musical legacy. His wife's book seems like the last word on everything else.