The unusual fluttery feeling throughout my body was unlike anything I'd ever experienced. My head felt swirly, and I had to fight to keep from tilting to the right. 

But I was too fascinated to be frightened as Mavis Pittilla, the grande dame of British mediums, told me that she could see two spirits, a man and a woman, standing beside me.

I wanted to have faith, but the fear that my experience was not up to the level of the rest of my class had been with me ever since the beginning of my week at the Arthur Findlay College of psychical sciences in Essex, world-renowned among mediums for the quality of its teaching.

Not far from Stansted Airport, the beautiful old house, which was set in acres of landscaped grounds, was said to have a vibration all of its own, built up from years of students working hand in hand with the spirit world, as I too had started to do following a dramatic change in the course of my life.

Thousands of miles from my home in Florida, I still found it challenging to reconcile my past self with the new direction I was taking.

The journey from Navy commander and commanding officer to medium would be unusual enough, but I had served at the highest level of the military as senior aide to the head of the entire United States Armed Forces.

On 9/11, I had been on my way to Europe with my boss, the chairman of the Joint Chiefs of Staff – the top-ranking officer in the United States Armed Forces – where later that week he was to have been knighted by Queen Elizabeth.

We were a couple of hours over the Atlantic when we got word about the terrorists' attack on New York. I put on a headset and spoke with a colonel back at our office in the Pentagon. As he filled me in on what he knew, I heard what sounded like a bomb exploding in the background.

Of course, it wasn't a bomb. It was a jet slamming into the far side of the building we'd left only a few hours earlier. Minutes later, when my general gave me the nod, I went to the cockpit and told the pilot to take us back to Washington.

'Commander, our flight path is going to take us directly over Manhattan,' he said. And that's how the handful of us on that aircraft became the only people in the country to see both the burning towers of the World Trade Centre and the Pentagon with our own eyes on the very day of the attacks.

A few thousand feet below, smoke billowed upward from what remained of the World Trade Center towers. I felt numb as I peered through the tiny window of our specially configured C-135 executive transport jet.

Our Air Force pilot had told me that we were the last aircraft in US airspace. All others had been grounded by then, including the President's.

I watched the aircrew open the safe in the cockpit and take out their authentication tables. I listened, incredulous, as they broadcast the coded information into the radio while we flew south to Washington.

This was a scenario I'm sure they'd practiced many times, but this was no drill. Their transmissions that morning ensured that fighter jets wouldn't shoot down our plane.

Arriving at the Pentagon shortly after American Airlines Flight 77 had crashed into it, killing all 64 people on the plane and 125 on the ground, had been like stepping on to the set of a disaster movie, the exposed beams, broken windows, and blackened limestone creating a painful portrait that my brain struggled to accept.

As a high-ranking official, I had to return to work. Tangibly aware of death all around me, I found it hard to stay focused. Smoke hung heavily in the air, seeping into my clothing and hair. I wished I were anywhere else. All that seemed very far away as, sitting on a small raised platform in the Arthur Findlay College library, watched by Mavis and a semi-circle of my classmates, my right index finger suddenly jerked upward and returned to its original position as if it had a mind of its own.

Next, with no effort on my part, my right hand rose ever so slightly; then my arm slid off my lap and hung limply at my side. I willed myself to stay calm.

My index finger twitched again and a singular thought blazed through my brain: I did not do that. Nor did I consciously do what followed. Slowly, as if not attached to me, my right arm rose a full foot to the side, coming to hover at a 45-degree angle from my body.

I felt resistance from beneath it, as if it needed an effort to push it back down, and realised that a spirit was holding it up.

The enormity of the experience suddenly overwhelmed me. Mavis must have felt this, because I could hear her stepping closer as she said, 'Slowly... slowly... relax...'

It was too much. I broke the connection and my arm fell to my side. I slumped forward, put my head in my hands, and burst into tears. 'I didn't do that,' I sobbed as Mavis put her hand on my shaking shoulders. 'That wasn't me.'

'Of course you didn't, my dear,' she replied. 'You did very, very well.' Her words only made me cry harder.

Suddenly, for the first time since I had embarked on the journey which began with the death of my stepdaughter Susan, I had no doubt that the spirit world was real.

Although I had no children of my own, I shared the love of Susan and her elder sister Elisabeth, my husband Ty's two daughters from his previous marriage.

Like Ty, the captain of a destroyer, Susan had dedicated her life in service to her country as a sergeant in the United States Marine Corps and after marrying in December 2005 had wasted no time in starting a family.

While she was revelling in the baby bump beneath her uniform, Ty and I were cruising the Adriatic Sea on our 46ft yacht Liberty, having retired soon after the events of 9/11 had shown us that we should make the most of life while we could.

Anchored off a deserted island in Croatia, I had a strange dream. I was at a party with people I didn't know when Susan stepped out of the crowd and said with a beautiful smile, 'We're fine. The baby and I are very happy'.

The dream was so realistic that I shared it with Ty as soon as he woke up.

The technology for making phone calls from a boat was then primitive but I felt the dream was trying to tell me something, and I said to Ty, 'We need to email Susan'.

He did so that morning, but we knew it would be a while before she responded.

Two days later, we received a reply from Elisabeth, asking us to phone home. When we finally reached a town with a payphone and Ty dialled home, with me standing next to him, I heard him cry out 'No! Not Susan!' and slump against the booth.

'Susan is gone,' he said.

Clutching each other in anguished disbelief, we shared the phone and learned more details. Our beautiful young sergeant had been reporting for duty, crossing the flight line outside her squadron's hangar.

She was in a hurry to greet her Marine husband, who had worked the shift ahead of her. The sky in the distance was dark, but it wasn't yet raining.

Suddenly, a jagged streak of lightning reached down from the clouds, striking Susan to the ground in what was literally a bolt out of the blue.

Fellow marines who witnessed the strike ran to her side and initiated CPR. Medical personnel at the hospital worked on her for seven hours, but there was nothing they could do for Susan or the baby.

When we finally got back to the US, the viewing at the funeral home was meant to give us a sense of closure, a chance to say goodbye. For me, it served an unforeseen purpose that would change the course of my life.

I had seen lifeless bodies before, but the transformation in Susan was shocking. Even though I was alone, I spoke aloud the thought that assaulted my brain: 'That's not Susan... that's not Susan...'

In that moment of clarity, I knew that what I was looking at was merely the vessel that had lovingly housed my stepdaughter's spirit for 27 years – a spirit far brighter than the bolt of lightning that had changed our lives in an instant.

Yes, the body before me would return to ashes but I realised then that Susan's spirit could never be destroyed. If there was a way of contacting her then I was going to find it.

On the way back to Croatia after the funeral we had stopped off in Venice to decompress and we were sitting on the balcony of our hotel when I suddenly heard the TV come on in our room.

Confused, I turned it off and returned to reading Walking In The Garden Of Souls, the first of three books about the afterlife I'd bought at the airport.

The very next paragraph made me stop and go back to reread the words.

With flawless timing, the author George Anderson confirmed that those in the spirit world often let their loved ones know they're around by manipulating lights, electrical appliances and electronic equipment.

'My God, Ty, listen to this,' I said, and read him the quote. He looked a bit nonplussed and I knew that I was in a vulnerable position – wanting so badly to receive a sign from Susan that she was around us in spirit. I sat back and closed my eyes. Was this just a coincidence?

Back on the boat, the painful memories still lingering in the air, we'd lost all desire to stay in Croatia and were heading south when Ty asked if I'd noticed the yellow butterfly that had been following us since we left shore.

The nearest land was four miles away and as I returned to Lessons From The Light, another book by George Anderson, there on the very page I'd been reading was a message straight from Heaven.

'My God,' I said for the second time in a week, 'listen to this...'

I read aloud George Anderson's timely claim that 'signs from the Infinite Light can often be right under our noses... as subtle as a tiny butterfly in December.'

Ty blinked in surprise, looked aft, and said, 'Or on the Adriatic Sea?'

Was it yet another coincidence? A fluke of nature? If so, then what about the swarm of yellow butterflies that hovered above our boat and no one else's as we arrived at the island of Mljet later that day?

The next morning, Ty and I set out on a hike through the woods and up to Mljet's highest point.

Still dazed and numb, we walked in silence. Instead of staring at my feet, I focused pointedly on the trail ahead and willed Susan to make her presence known to me.

Higher and higher we climbed, and with each step I grew more despondent. Why couldn't I sense her?'Susan,' I prayed, 'please give me some kind of sign that you're around. We so desperately need to know that you're not gone forever.'

Just then, a flicker of movement from the left caught my attention. I turned my head and saw a yellow butterfly flying straight at me.

It arrived at my side, flew a complete circle around me, then bounced into my chest at the level of my heart.

I stopped in my tracks and watched, stunned, as the butterfly then flew in a direct line down the trail toward Ty. Incredulous, I called out his name.

The shock in my voice caused him to stop and turn as the butterfly bounced into his back, again at heart level, before flying off into the woods.

There was no doubt in my mind that something spiritual was going on and that Susan was behind it. God was my witness, and – thank goodness – so was my husband.

I decided that our next step was to find a medium. Whoever I chose had to get past the sceptical minds of two career naval officers and back home I got in touch with Sophy Burnham, who was based in Washington DC and not only a medium but a best-selling author of books about spirituality.

With Ty driving, I spent the journey there drumming my fingers nervously on my thighs, well aware of how much hope I was placing on one woman's abilities. I kept up a continuous silent prayer to Susan not to let us down.

Sophy informed us that she normally read for only one person at a time, so I sat with her first.

Without notice, she squinted and asked, 'Do you have a headache? I have a tremendous headache suddenly, and I'm tingly all over, like little electrical impulses.' I felt a chill. I knew that mediums will often sense how a person died from a physical sensation within their own body. The electrical feel would be from the lightning that had struck Susan in the head.

'I can't express it exactly,' she said, 'but it's like the headache of Zeus and Athena.'

My memory of mythology was a bit weak, but I knew who Zeus was: the god of lightning bolts.

I pictured the mighty figure standing atop a mountain holding a jagged bolt of lightning just like the one that had struck Susan, and the tears began.

'There's someone here who wants to speak to you,' she said, 'but I'm not getting very much except a little tug, like this...' She tugged at her sleeve. 'And it's a young girl in her 20s, a relative who died unexpectedly.'

My throat instantly constricted. If Sophy had wanted to give a fake reading, she only had to tell me that she sensed a great-grandmother with grey hair who had died when her heart gave out.

Anyone could make up that kind of detail. What she'd told me was exactly what I'd been praying to hear, with accuracy no one could fake.

What Sophy said next turned my tears into sobs. 'And now there's a second person, a child she's holding by the hand. And she's saying: 'Don't be unhappy. Don't cry.' '

Not crying was impossible. 'Just tell her to stay here for her dad,' I said and called Ty who took a seat in the empty chair across from Sophy.

She then described Susan correctly as a nice-looking girl with brown hair and a brown uniform, just like our young Marine sergeant wore.

'And this is your daughter, isn't it, because now she's saying, 'Daddy, Daddy.' It was Ty's turn to choke up. 'She just wants to sit on your lap and wrap her arms around your neck,' Sophy said, describing exactly the way Susan used to embrace her dad, even at age 27.

'The child, meanwhile, has been doing almost nothing except looking at you, sucking his thumb, very shy and looking to your daughter for directions.'

It was almost too much to bear. The ultrasounds had shown the baby would be a boy. They had decided to name him Liam Tyler.

In the days and weeks following the reading with Sophy, my hunger and longing to know that Susan's spirit survived was replaced with thirst about how I could develop my own spiritual gifts. That is what had brought me to the Arthur Findlay College. At the end of my week there, Mavis Pittilla asked us to give private readings to each other.

Since we had been told not to interact outside of the classroom, we knew little about each other but as I sat across from my classmate David I sensed the presence of a younger man related to him and knew they were brothers.

David confirmed that he had a brother in the spirit world.

'I'm seeing him in a pub,' I said. 'Leaning on the bar as if he's really comfortable in this place.' David laughed. 'That would be him.'

Stunned by the clarity of the connection, I described the full-colour images arising in my awareness.

'He's tilting back a big pint of beer, as if to show me that he really enjoyed a pint or two... and he smoked. In fact, that's how he died – from a problem with his lungs from smoking, isn't it?'

'Yes, it is.' Widening the lens, I saw a wooden sign hanging outside the pub. In the centre of the sign was an elaborate coat of arms in red and black, and across the top were black letters. I caught my breath, for I could clearly read the words. I felt like a gameshow contestant going for the final prize as I said, 'The name of the pub where your brother hung out was The King's Arms.'

David knew how much that piece of evidence meant to me. He beamed back at me and nodded. 'That's right.'

I raised my eyes to the heavens and squeezed them tight. No A in school had ever felt so good and the path which would lead me to Susan now seemed well and truly open.

Adapted from Making the Afterlife Connection by Suzanne Giesemann (Hay House UK, £14.99), to be published June 10.

© Suzanne Giesemann 2025. To order a copy for £13.49 (offer valid to 21/06/25; UK P&P free on offers over £25) go tomailshop.co.uk/books or call 020 3176 2937.