Kate McCann was stuck in an "endless bad dream" and haunted by visions of her missing daughter Madeleine after her disappearance, it was revealed today.
In a personal account of how the three-year-old vanished on a 2007 family holiday to Portugal, Mrs McCann described how she immediately feared that the youngster had fallen victim to a paedophile.
In an extract from the book, which is entitled 'Madeleine' and released next week, the 43-year-old said: "The truly awful manifestation of what I was feeling was a macabre slideshow of vivid pictures in my brain that taunted me relentlessly.
"I was crying out that I could see Madeleine lying cold and mottled, on a big grey stone slab.
"The pictures I saw of our Madeleine no sane human being would want in her head, but they were in mine.
"I simply couldn't rid myself of these evil scenes in the early days and weeks."
The book's release comes almost four years after the three-year-old vanished. It was written by Mrs McCann using her personal diaries.
In another extract, serialised by The Sun today, Mrs McCann revealed that her husband Gerry was also wracked with similar harrowing thoughts and visions.
Mrs McCann wrote: "I asked Gerry apprehensively if he'd had any really horrible thoughts of visions of Madeleine.
"He nodded. Haltingly I told him about the awful pictures that scrolled through my head of her body torn apart.
"Later on it was the nights that were the worst. Not only did lying awake in the dark take me straight back to the most awful night of all, but my brain, finally free of the preoccupations of the day, would wander unbidden down black and terrifying avenues.
"I struggled constantly to think nice thoughts and drift off to sleep, but the demons had me in their grip and would torture me mercilessly with images too frightening and painful to share."
Mrs McCann, from Rothley, Leicestershire, also lays bare how she wanted to kill and "inflict the maximum pain possible" on the person who had abducted her daughter.
She added in another extract: "Once we did begin to function within what felt like a endless bad dream, we started to comb through our memories searching for something significant.
"When she was first stolen, paedophiles were all we could think about and it ate away at us.
"The idea of a monster like this touching my daughter, stroking her, defiling her perfect little body, just killed me over and over again.
"I would lie in bed hating the person who had done this to us - the person who had taken away our little girl and terrified her."
The book also criticises the Portuguese authorities, who shelved the investigation into Madeleine's disappearance in July 2008, for failing to investigate other alleged child abductions thoroughly.
It also documents the moment Mrs McCann discovered that her daughter had vanished from their apartment in the resort of Praia du Luz and the frantic search that ensued.
The former doctor, who had been dining with her husband and seven friends at a tapas restaurant 100 metres from the youngster's room, said: "When I realised Madeleine wasn't actually there, I went through to our bedroom to see if she'd got into our bed.
"On the discovery of another empty bed, the first wave of panic hit me.
"Nausea, terror, disbelief, fear. Icy fear. Dear God, no! Please, no!"
Proceeds from the 384-page book, which Mrs McCann has written herself without the aid of a ghost writer, will boost the dwindling fund to search for her daughter.
The McCanns also hope that the publication will prompt people holding vital information about what happened to the child to come forward at last.
It has a recommended retail price of £20 (€22.87) and is expected to become a best-seller.
The book was originally due to be published last week but publishers Transworld postponed the release date to May 12 - Madeleine's eighth birthday - to avoid clashing with the royal wedding.
Madeleine was nearly four when she vanished from her family's holiday apartment in the Algarve on May 3, 2007.
Despite a massive police investigation and huge publicity worldwide, she has not been found.
Private detectives employed by the McCanns have continued the search after the official Portuguese inquiry was formally shelved.