By his bedside in his comfortably-appointed cell at Maghaberry jail, born-again killer Colin Howell will doubtless have a special place reserved beside his Bible - and his porn stash - for Deric Henderson's new book about him, his demons and his demonic deeds.
It tells the still scarcely-believable story of how Howell, aided and abetted by fellow Christian - and mistress - Hazel Stewart, callously killed their spouses and buried the truth with them for 18 years by making the deaths look like a suicide pact.
In a Troubles-hardened province which had thought itself shock-proof to any new barbarities, the courtroom revelations inside the last year about the depravity of Howell and Stewart caused a sensation and were a talking point in virtually every home, office, pub and restaurant.
From the outset, award-winning journalist Deric Henderson suspected the saga of betrayal, sex and murder in the Bible belt was a bestseller waiting to be written.
And he was right.
Howell, the pornography-obsessed and greed-ridden Ballymoney dentist who was the very antithesis of the Christian faith he so publicly and proudly espoused, once boasted he would write his own book. His way. Which is very definitely not Henderson's way in Let This Be Our Secret.
Howell, now serving 21 years for the killings, refused to co-operate with Henderson and he'll probably take exception to much of what he's written.
But he can hardly argue with his depiction as a self-centred monster who carefully planned the deaths of his wife Lesley and his lover's husband Trevor Buchanan by gassing them in their Coleraine homes in May 1991.
Despite his disdain for the book, people who know the one-time wannabe missionary say that the egotistical Colin Howell will love seeing his name in the headlines again and realising that a record of what could have been his perfect murders is now writ large in the annals of criminality.
A couple of months ago, a prisoner in Maghaberry told me that Howell was revelling in his notoriety, especially in the aftermath of his sensational testimony in the witness box of Coleraine Crown Court against his former lover Hazel Stewart.
The inmate said that most days Howell strutted around the jail but he was even more puffed up than usual on the evenings after he gave his evidence, knowing that his fellow prisoners had been following television reports of his 'performances' which sealed Stewart's fate.
Her attitude to Henderson's book will be unequivocal. The former Sunday school teacher who still sees herself as more sinned against than the sinner the jury found her to be, despises anything that portrays her as Howell's willing partner in crime
Particularly damning is the contribution of another man who shared her life for eight years.
In his interview with Henderson, Trevor McAuley would only refer to his ex-lover as Buchanan. And he branded her cold-hearted and materialistic, a woman whose dark moods could only be lightened by spending money. His money.
Friends say it's possible Stewart may not even read the book, preferring to live in the sort of denial which Henderson says has been her trademark from the time she first had sex with Howell but bizarrely didn't believe they'd actually consummated their relationship.
For relatives of the innocent victims of this sordid tragedy, the book obviously can't be anything but a painful re-awakening of the savagery and deceit that not only ripped their families asunder but also prolonged their agony after the cloud of suicide hung over the deaths until Howell made his startling confessions to murder in January 2009. But what's striking about the book is the humanity and compassion in its telling. I've known and worked with Deric Henderson for nearly 40 years and he's never been a man to underplay a good story by ignoring a punchy turn of phrase to hammer home a powerful point.
But in Let This Be Our Secret he deftly veers away from the temptation to titillate or to sensationalise, clearly keen to ensure that the trust placed in him by the victims' families in opening their hearts to him was not misplaced.
Indeed, in the book Henderson, a veteran of four decades of reporting the worst of Northern Ireland's terrorist-related obscenities, shares an excruciatingly harrowing moment which, he says, topped anything he'd experienced during the Troubles.
It came as Trevor Buchanan's brother Victor was telling Henderson how in 1991 his father, clearly accepting Howell's lie that his policeman son had indeed taken his own life, reached into his coffin and held him in his arms, crying out that he could have helped him if only he had told him about his emotional turmoil.
Henderson had to walk away to compose himself. For the first and possibly the last time in his reporting career.
In recent months, Henderson - in his day job as the Ireland editor of the Press Association - has already written tens of thousands of words about the court appearances by Howell and Stewart and about what led them to the dock.
Which left many of Henderson's sceptical colleagues wondering what more could be said in a book about one of the most closely examined and debated scandals in the criminal history of Northern Ireland.
But while even Henderson concedes he isn't pulling any eye-popping revelatory rabbits out of the hat, his book is an important and definitive account of love lost and lust found by the mendacious Howell and Stewart.
And all this set against a backdrop which rarely comes under the spotlight here - the happy-clappy and oft-times impenetrable and small-minded world of Protestant religious sects more used to puritanism than the pure evil personified by Colin Howell.
Henderson may have been left with few major surprises to impart to readers who've followed every twist and turn of the courtroom dramas.
But it is the Omagh-born writer's meticulous attention to detail about the ostensibly ordinary lives of Colin and Lesley Howell and Hazel and Trevor Buchanan which makes the book impossible to cast aside as he completes the jigsaw of how justice was finally done.
Of course, the murders themselves still defy belief no matter how many times they're re-told.
I read Henderson's book just after returning from a two-week sunshine break where I devoured a veritable library of whodunnits and thrillers.
But none of the fictional plots came even close to the reality of Henderson's gripping narrative.
And my bet is that Henderson's book will be turned into a TV or big-screen film with actor Jimmy Nesbitt surely born to play the role of Howell who lived and executed his killings on the Cold Feet star's very doorstep in Coleraine and Castlerock, where the suicides were faked behind a row of houses aptly-named the Apostles. It's a casting of which Howell would probably approve.
Unlike his distaste for how he was portrayed by an unknown actor in reconstructions for a recent award-winning BBC documentary.
Like that programme, Henderson's book doesn't pretend to be the final chapter on Colin Howell and Hazel Stewart, who is currently working on an appeal.
Henderson says there are still questions to be answered about the original shoddy police investigation into the supposed suicides, a probe which is expected to be heavily criticised soon in a report from the Police Ombudsman.
Henderson also examines the fall-out within the congregation of Coleraine Baptist Church over how their leaders dealt - or didn't deal - with their knowledge of the love affair between Howell and Stewart.
One criticism of Henderson's account of two star-crossed lovers who broke every commandment in their good books to rid themselves of their cuckolded partners is that there's not enough of it.
There's a nagging feeling that while Let This Be Our Secret is a superbly-researched insight into a shocking and ultimately disastrous head-on collision between love and death, there's more - much more - he could tell.
Especially about Hazel Stewart who's serving 18 years in Hydebank Women's Prison which is - as the crow flies - just a few hundred yards away from my home.
As I scan the heavens every morning from my back window to see what the weather holds in store, I sometimes muse that Hazel Stewart will probably be looking at exactly the same piece of sky as me.
And as I finished off Let This Be Our Secret, I wondered if my neighbour's potential appeal had constrained Henderson from disclosing chapter and verse about this shadowy half of a double act who would have got away with murder if Howell hadn't come clean, be it through conscience or caprice.
Perhaps Deric Henderson might have ended his impressive and arresting book with the three-letter indicator that old school journalists like us used to send to sub-editors to inform them that we hadn't finished the whole story.
"MTF" meant more to follow ...