They were intended as encouraging words of farewell. Uttered as a kind of salve – if any could exist – to the looming horror ahead. 'In October, I’m coming back to visit you,' said Marcy Wilson, as she sat in a small visiting room in the maximum-security confines of the Debra K Johnson rehabilitation centre, in Nashville, Tennessee.

Sitting in the room with Marcy, a 60-year-old mother, was Christa Pike, a convicted killer who, four days later, was scheduled to become the first woman to be executed in the state of Tennessee in more than 200 years.

Marcy, who’d become one of Pike’s closest friends, having forged an unlikely bond when her own troubled daughter was incarcerated with the now 50-year-old death row inmate, was trying to tell her not to give up hope. That there might be a last-minute reprieve.

She didn’t truly believe it, of course. Nor, it seems, did Pike. Sentenced to die three decades ago for the chilling, sadistic murder of a fellow college student, she knew her time was up, she was at peace and, says Marcy, 'ready to go'.

Although no reprieve, in the conventional sense, came, what followed was more extraordinary than anyone could have imagined.

Pike managed to survive two doses of the lethal injection pentobarbital on September 30. Today she lies shackled to a bed in a heavily guarded room, in a hospital in Nashville, ‘confused and angry’, according to her lawyers.

Marcy, meanwhile, remains haunted by the prescience of her final words of comfort, as she waits to hear when, or if, she’ll be able to fulfil her promise and visit her friend again.

Speaking exclusively to The Mail on Sunday, Marcy says: ‘I cannot even begin to imagine what our first conversation is going to be like. But it’s going to be absolutely wonderful.’

Since that botched execution, the world has been held in a state of macabre fascination, torn between sympathy and outrage.

Today, experts who wanted to kill her have been replaced by those who want to save her. For now.

She has a blood clot, her hands are swollen to resemble inflated rubber gloves and are marked by what appear to be severe chemical burns, mostly likely caused by the highly alkaline, bleach-like drug spilling into her flesh instead of straight into her bloodstream as intended. She has, however, begun to eat and to walk.

‘Her physical recovery has been remarkable,’ say her legal team.

What the long-term effects may be – physically and psychologically – remain unclear. While the spotlight is firmly fixed on the ethical and legal questions around the botched execution, the status of her sentence is also uncertain.

Of course, many will point out that what Pike has endured pales next to the crime she committed back in January 1995, when she and two accomplices lured 19-year-old Colleen Slemmer into woodland, where she was bludgeoned to death. While she was still alive, a pentagram symbol was carved into her chest with a box-cutter. Pike even kept part of her victim’s skull as a twisted souvenir.

Marcy, one of the last people to speak to Pike over the phone on the eve of the astonishing debacle 11 days ago, knows many will struggle to understand her friendship and affection for someone capable of such a heinous crime. But her support transcends all moral argument, and the rights and wrongs of capital punishment.

‘She’s a survivor,’ she says tearfully - the irony of those words not lost on her.

Christa Pike is indeed a survivor, in uncharted territory. While there have been other bungled execution attempts (the execution of fellow Tennessee inmate Tony Carruthers was abandoned earlier this year after his executioners failed to find a vein), she is believed to be the only person to have survived lethal injection.

The past two weeks have been a blur, says Marcy.

‘It was bad news one day, good news the next,’ she says. ‘The hospital declared her brain dead on Monday night and then she wakes up talking the next morning…

‘It makes me wonder. Did they even do a test on her brain or were the authorities just trying to get her off the ventilator?’

Pike’s half-sister Alicia, who flew from her home in Hawaii to be at the execution, is believed to have power of attorney for her younger sibling and would have been the one to give the go-ahead for life support to be switched off.

At one point, Pike’s legal team were getting ready to make the death announcement, before things changed drastically.

‘Where am I?’ and ‘Who are you?’ said Pike when she woke at around 9.30am on Tuesday.

Marcy, so close to Pike that she has three of the murderer’s ‘beautiful’ paintings in her home, has been kept updated. She admits she was aghast when she learned, back in 2017, that her troubled daughter Teddy, who had become addicted to prescription drugs, had been transferred to maximum-security Debra K Johnson prison. She was horrified further when she learned with whom she was sharing a wing.

To her surprise, Pike sent Teddy shower shoes when she didn’t have any, a gesture that brought about an unlikely friendship between the two women. Marcy sent Pike a letter of thanks, forging their own bond, which continued even after Teddy died in 2023, aged 32, from a fentanyl overdose.

At first it was letters, then Pike began to call, once a month, sometimes more, using her limited prison savings. They met for the first time in 2017, and started meeting regularly earlier this year.

Marcy recalls her last visit, a three-and-a-half-hour meeting.

‘I was led into a small room and I got to hug her. We sat close, we got to touch each other. We had snacks. I prayed with her.

‘I was dreading it, I was thinking, “Oh my God, three and a half hours is a long time”. But Christa made the time go by so fast. We talked about happy times, different things that happened when she and Teddy were there together.’

Though others may find it strangely unsettling, Marcy says the woman she got to know cared deeply for others and who loved animals and drawing pictures of mermaids. ‘I would send pictures of the animals on my farm, and she would give them names and ask about them. It was a way for her to live outside the walls,’ she recalls of the inmate who spent 27 years in solitary confinement.

‘I’m in the process, hopefully, of adopting a thoroughbred broodmare and I knew Christa needed something to keep her mind occupied [in the run-up to the execution], so I messaged and said, “I’m getting this jet-black mare just for you and I need a name for her.”

‘When I went up for the [last] visit, she said she had come up with the name: Nyx. Christa’s of Greek heritage and Nyx means black or dark.’

Amid all the chat about the farm there was talk, too, about what was to come. ‘We were sitting there in the room and at one point she just crumbled,’ Marcy says.

‘It’s the most profound thing to be looking in the eyes of a condemned woman.’

At one point Pike asked Marcy: ‘Do you want some of my ashes and a lock of my hair?’ ‘I said, “Yes, I do”,’ recalls Marcy, again in tears. ‘It was really hard to talk about. I’ve never had a conversation with someone who knew when her expiration date was.

‘She was pleased when I said yes. She was calm, she was happy, she was sad. It was every single emotion you can think of.

‘She told me, “Marcy, I’m not afraid to die. I’m just afraid of the process”. She was afraid because of the pain. So many people have made comments like, “Look at the pain that she put her victim through,” and those are valid statements, but it’s only human for her to be afraid of pain.’

But what of remorse? Her victim’s mother May Martinez has decried the absence of any apology direct to her family. She travelled from Florida to Tennessee for the execution, wanting to hold her daughter’s photograph aloft while watching the woman who killed her meet her own end.

In the end, it was a torturous day – a last-minute stay of execution was overturned by the Supreme Court, before the execution began in front of seven media witnesses, legal representatives, May Martinez and family members.

To say May’s anguish has multiplied would be an understatement: ‘I think that the state owes me a big apology,’ she has said.

‘If I could have gotten in that room, I would have taken the box-cutter and cut her up like she did Colleen.’ Marcy, however, insists Pike remorseful.

‘She told me many times that she wished she could take back what she did. She was just months into being 18 when it happened and if she’d been a bit younger, it would have been a different outcome,’ she says.

She says that when she hugged Pike goodbye, her friend was ready for what was to come.

‘I don’t want you to worry about me. I’m ready. I’m good. Everything’s going to be OK,’ said the condemned woman.

They spoke again, on the eve of execution day. ‘We talked about how when she got to heaven she was going to find my daughter and they were going to ride horses,’ recalls Marcy. ‘She told me and my husband to take care of each other and that she loved us.’

Marcy’s compassion is palpable, and without being able to speak to her friend directly – Pike was unable to see even her legal team until a court ruling on Wednesday – Marcy can only guess as to her state of mind now. Pike’s lawyers say their client is ‘angry and confused’ and ‘continues to experience cognitive challenges with concentration and memory’. ‘Physicians have cautioned it may take months to fully understand whether she sustained lasting cognitive injuries,’ they say.

Her lawyers insist she ‘endured more than enough’, and that her sentence should now revert to life behind bars. Until the legal position is clarified, she remains very much a woman on death row.

Pike’s lawyers, apart from arguing that her age at the time of the crime and extensive physical and sexual abuse she suffered as a child should be a factor in determining the severity of her punishment, had warned that lethal injection was fraught with risk.

She had a blood disorder, they said, and her small veins created a heightened risk of complications, as well as the possibility of extreme pain and bleeding.

What exactly went wrong is yet to be determined. Tennessee governor Bill Lee has ordered an independent investigation and suspended all executions in the state for the rest of the year.

And yet, asked during a court hearing on Wednesday whether the state intended to reschedule Pike’s execution, the state’s attorney general said he did not know.

Joel Zivot, a professor of anaesthesiology and surgery in Atlanta, Georgia, was the medical expert who warned how much risk lethal injection posed to Pike. He’s vehemently opposed to any re-run.

‘I’ve always taken the position that this [lethal injection] really is an effrontery to the practice of medicine,’ he told the MoS.

‘This is a sinister impersonation of medical practice.’

Pressing ahead with the execution against all warning, was unforgivable and inevitable, he says. ‘As the day of the execution wore on, I was watching the clock and thinking, “Well, it must be starting now.

‘I sent an e-mail to one of the lawyers and said, “Can you keep me updated if this goes awry?” Because, you know, I thought it might. Within five minutes, he replied, “It has gone awry”.’

Prof Zivot knows all too well the damage pentobarbital can do – just as he knows that for medics helping Pike, only time will allow the poison to work its way out of her system.

He is aware, too, of the painful irony of efforts to kill Pike a fortnight ago and last week’s efforts to save her. ‘I suppose everyone was doing their job. The state was doing its job in trying to kill her and the doctors were doing their job in trying to save her,’ he says.

He points out one curious feature of this whole grisly debacle. The law, he says, requires that punishment not be cruel. But how can that be determined when the one person who really knows – the prisoner – dies?

‘Here’s an opportunity to ask someone, “What you were subjected to, did you experience that as cruel or not?” I’d like to ask her that question.’

For Marcy, she cannot wait to see her friend again.

‘She told me that she was going to come back and haunt me, but in a good way, and that made me laugh,’ she says.

What is clear is that Pike’s story and the growing debate over her punishment for the brutal murder of a young girl whose laughter was extinguished over 30 years ago, is far from over.