Caleb was in the machine shop on his break, and Wendy had arranged for me to talk with him there since he refused to come and see me in the office. “He’s anxious about this and a bit agitated,” she warned. We found him hammering a metal sheet on a workbench in a deserted warehouse space filled with machine parts. I said hello, but he didn’t acknowledge me. “Caleb, I know this isn’t easy,” Wendy said, “but we just discussed this, and you agreed.”

Her voice was kind but firm. Caleb shoved the metal sheet aside, and turned to face me. “All right then… let’s get this over with.” His voice was rough and unwelcoming, and I felt uneasy. I would have to try to establish a rapport. “Can we talk here?” I indicated the workbench. “Suit yourself,” he said.

He was in his mid-20s, but it would be easy to mistake him for a secondary-school student playing truant. His jeans sagged below his hip bones, and he was so thin and pale I feared he was malnourished. When he spoke, I glimpsed his missing teeth; there were at least three or four dark gaps.

“What am I meant to say to you then?” he asked abruptly.

I explained my purpose, adding, “I’d just like to ask about how you’ve been since the accident.”

He made a dismissive gesture. “Can’t you just put down that I’m feeling like s—? Why do I have to explain anything? They should explain how they let us go up in that chopper.” Caleb kicked the metal on the floor, causing a cymbal shimmer to echo around the open space.

Big, big fear there – and considerable anger, too. I suspected it flared often, probably ignited by almost any interaction; I was just his lightning conductor for the day. I could see how this interview might feel like an intrusive attack at a time when he was feeling vulnerable. “This process is awful, Caleb, I agree. Just say what you can.” He gestured at my notes. “Write this down, Doc. I want the helicopter company to pay up. And maybe” – the sweep of his arm took in the work area around him – “this lot, too. Some raffle prize, right? Company should have vetted them properly.”

Caleb then dismissed the notion of the helicopter having a mechanical failure, saying he knew a thing or two about engines. The problem, in his view, was that the pilot was “crap” and caused the crash because he hadn’t a clue what he was doing. I knew otherwise from the accident report but did not argue.

“Did they tell you I had a breakdown after?” he said suddenly, crossing wiry arms over his chest. I thought for a moment about how to answer. “Wendy mentioned you’d been struggling.” He glared. “Struggling?” His voice was sarcastic. “That what you call it? You can’t imagine. I’m lying there, mouth full of dirt, don’t know if I’m dead or alive, or if this is a bad dream or what, and then I saw it next to me and it…” He stopped again. “Her hand. Nails painted pink and all. Jesus.” His face was reddening, his jaw set.

I decided to move on to what came after the crash, noting that he’d returned to work quite soon after. “I need the job,” he said bitterly. “If I keep getting signed off sick, they’ll fire me. I can tell the company wants to get rid of me anyhow – they all think I should’ve died instead of her.”

His rage and paranoia were growing, pulsing, radiating from his body, and I was beginning to feel uncomfortable, a sensation I’d learnt to take seriously in my forensic training. I knew I should end the interview immediately. Nothing I could say would make him feel calmer or less afraid.

Just as I was thinking this, he confirmed it. “Shrinks… f—ing shrinks and lawyers!” His eyes were fierce, and flecks of saliva formed at the edge of his lips. “You’re all the same, you lot.” Instinctively, I drew back, and that’s when I saw his discarded hammer lying on the floor. I realised his eyes were on it, too. There was a pregnant pause – then he kicked it, sending it skittering across the floor, shouting, “I’ve had enough!” before stalking off.

Caleb needed urgent help. He presented a risk to himself and others and shouldn’t be in a workplace where many tools could be used as weapons.

The next day, Wendy rang to tell me that he’d been admitted to a psychiatric hospital, detained involuntarily and diagnosed with paranoid psychosis.

Follow-up assessments

I didn’t think I needed to meet with Lisa again, but I asked if I could see Martin for a follow-up and as soon as he arrived, I noticed a difference in him; he seemed much more present and alive. He shook my hand and immediately made eye contact, saying he felt better.

Martin’s GP had changed his meds for depression and got him some cognitive behavioural therapy, which had made a big difference. He’d given up his job and he and his family were moving to Kent. I could see he was still a saddened man, much altered by his experience, but I felt heartened that he seemed more engaged in the business of life.

Before I followed up with Caleb, I was able to request and review his GP’s notes and found that he’d been known to the child protection services, and some reports referred to him being taken into care briefly as a boy. I also saw a couple of assessments by child psychiatrists who had seen him years earlier – presumably, the first of his “f—ing shrinks”.

Eventually, I heard from Wendy that Caleb was about to be discharged from the hospital and was ready to meet with me again to complete our assessment. When I arrived at the psychiatric facility, I noticed immediately how his appearance had changed. He’d put on weight – a side effect of the anti-psychosis drugs – and it suited him. His attitude was also entirely different: he welcomed me with a smile and a handshake, and swiftly apologised for his sudden exit from the factory that day. I wasn’t surprised to find him so altered; it’s not unusual for acute psychoses to resolve just as quickly as they start, with medication and appropriate care. None of this meant that Caleb had left the trauma behind; he might just be able to speak about it now.

This time, he seemed more sad than angry, and when I asked him about his worst moment, he spoke again about seeing poor Terri’s severed hand, and how he would never forget it.

He started to tell me a little about his early life. His mother had run away from home when she became pregnant at 16, finding work in a pub in London. She often dated men she met there, he said, adding, “I was scared of them, and of her, too. She’d go on the piss and scream at me… And then her boyfriends beat her up sometimes, in front of me.” They had also beaten him. “See here?” He pointed to the gaps in his teeth. “I’d only just grown in my big teeth when one of them did that.” He ran away from home and ended up in care, until his mother found safe accommodation away from the pub. He did an apprenticeship that would ultimately lead to his job at the kitchen factory. “I was hired just in time to go along to the Christmas raffle, wasn’t I? Lucky me.”

I asked if he thought he was ready to return to work, but he’d decided to follow his doctor’s suggestion to continue with rehabilitation a little longer. I felt I could now give him the PTSD symptom checklist. In the “past” column, he ticked “intrusive images” – that severed hand had been persistent, although it was now largely gone.

“But I’ve got something else that isn’t on your list. I still don’t feel right. I feel like a snail without a shell,” he said. He told me about memories of how his mother would sometimes lock him in his room all day. He was worried that when he left the facility his rage might boil over, at her. I was seeing him as an independent expert, not a therapist, and I had to be careful not to step outside my role. I told him to consider staying at the facility and having more therapy, looking at his childhood fears as well as the crash. I didn’t add that I had plenty of evidence that he had suffered a significant psychological injury because of the accident, affecting his day-to-day functioning, especially his work. I thought that when the court came to allocate damages, Caleb would get more than Martin or Lisa, and I hoped he would use that money to continue his recovery after being discharged. I would highlight his need for long-term therapy in my report.

When I finished my assessments, I sent them to Wendy and my work was submitted into evidence.

Settlements and the aftermath

More than a year later, there was, as predicted, a settlement, which, to my relief, meant that I would not have to go to court to defend my opinions. As I had guessed, Caleb got the most significant amount, Martin a similar sum, and Lisa somewhat less. That seemed a bit unfair to me, with Lisa’s resilience meaning she was compensated less than the others.

These three crash survivors could be considered fortunate, despite their ordeal. As Martin had said, they were the lucky ones. They were alive. But this might be all they had in common; three people could have almost the same traumatic experience but with three very different survival reactions. It was plain that emotional stressors and lack of childhood attachment security are significant risk factors that make a difference in how resilient you might be to major trauma. Lisa seemed the “luckiest” in that regard; that’s why I thought she had suffered but recovered. Today, I know better than to think that trauma stories always end so neatly.

About three years later, I received a call from a psychiatrist in Birmingham who ran a perinatal service looking after new mothers with mental health problems. She told me she was treating Lisa for acute post-partum psychosis.

My colleague knew about the helicopter crash and had gained permission to discuss Lisa’s case. She was very unwell now, ever since the birth of her daughter six months prior. “Severe depression, believing that she and the baby are about to die, hallucinating that their bodies are decomposing. Her husband thought she was going to bury the baby alive.” I struggled to reconcile this presentation with the Lisa I’d met. Something macabre was bursting out of her memory and manifesting as a paranoid belief that both she and her baby were dying or dead.

Lisa had not mentioned the helicopter crash in her antenatal clinic, and it had taken another life-changing event – albeit something positive – to bring this acute response to the fore.

As it happened, I was embarking on some research into maternal violence and its motives, and discovering more about how “matrescence” – the transition to motherhood – can be a potent psychological stressor, even when the pregnancy and the baby are much wanted. My continued research in this area and my work in the family court would reinforce the idea that there is nothing like a pregnancy for activating memories of being vulnerable and making mothers-to-be aware of the potential fragility of life. Rather than “grounding” women, maternity shifts self-perspectives and memories, like tectonic plates moving in the deep unconscious.

I told the psychiatrist that there had been no sign of any persistent mental health problems when I interviewed Lisa. She had successfully avoided engaging with her sense of fear, which meant I saw only her briskness and lucidity, her faith in a positive future. With hindsight, when I recalled how she described her sense of helplessness and that distorted sense of time in the absolute silence after the crash, I realised I had missed something darker. How remarkable the process of encoding and retrieving memories can be; the more I learn about this, the less I think I know.

The perinatal psychiatrist and I kept in touch, and in time she told me that after specialist treatment and care, Lisa made a good recovery and went home with her baby girl. Lisa’s story made me reconsider some important ideas, and it has stayed with me even now because of the mystery of that acute contrast between her response to the crash and her reaction to becoming a mother. Was she just lucky with helicopter crashes and unlucky with the transition to a new identity as a mother? I am left to wonder whether traumatic memories somehow hide in the mind. But if so, where? All I can say with certainty is that recovery from trauma sets its own timeline, a trail that may bend, incline or twist without warning.

*All names have been changed

Extract from Unspeakable: Stories of Survival and Transformation After Trauma by Dr Gwen Adshead & Eileen Horne (Faber, £20), which will be published on Feb 26