Chapter 1

Sarah

A sudden jolt, blinding light pierces my eyelids, and I swallow down my claustrophobia. I try to calm my breathing as my stomach lurches. I bite down hard. The sound is deafening and my fists are clenched at my side. I lie still and try to block out the noise. I'm trapped, forbidden to move, not even one muscle. Breathe: In . and . hold. Oh God, I need to get out of here.

Hard plastic presses into my shoulder blades and pelvis. I am meat on a slab. Suddenly, the whirring vibrations stop, and I'm plunged into silence and darkness. Is it over? My body starts to slide, cold air enveloping me as I'm carried towards the light. I hear the door open, followed by footsteps. Then, a voice.

'Sarah, there's a malfunction with the machine. Are you OK to stay where you are for a few minutes? I'm just going to reboot the system, but we'll have to re-scan. I don't want to risk compromising the result. I'm so sorry about this.'

'It's OK, Karima, I'm fine.'

I'm really not fine. Not fine at all.

The slab that I'm lying on continues to move, spitting me out from the MRI chamber. I sit up and try to regain my calm. At the end of the room there is a window into the control area, and I see my husband, Daniel, leaning over the computer, studying something on the screen. He stands with his arms folded as Dr Karima Falka returns. Daniel catches my eye and offers me a reassuring smile, but he can't disguise his sadness. This day is something neither of us was ready for. A few moments later, Karima returns to the scanning room.

'OK, we're back on. Can you lie down again for me, Sarah?' Her soothing Scottish accent reassures me. As I obey, a crackle of static electricity sends a shock wave up my spine.

I flinch; my voice is tight. 'Is Dan OK?' There is a pause. Maybe she didn't hear me. 'Karima?'

'Yeah . he's . good. You're doing really well. Not too long now and we'll have you out of here.'

The door closes and I feel that ominous magnetic hum of the MRI chamber gathering speed as the slab slides back into the void. My toes curl, and once again I'm plunged into the jaws of the machine.

Whatever happens, babe, I'll take care of Maddie - you and Maddie. We'll get through this.

Of course, Daniel had already jumped to the worst-case scenario. I had a more optimistic view, but that's us in a nutshell: poles apart. He's a worrier. I just don't think in the same way. I truly believe this will be OK. I have to. But things have started to happen that can't be ignored. First, it was simple things like driving to the supermarket and forgetting which vehicle was mine in the car park. I spent half an hour walking around randomly clicking the key fob. 'Of course, the red Audi.' Then there was the time I forgot to pick Maddie up from school. I wrote it off as 'just one of those things', but if I'm completely honest with you, and I have never told another soul this, when it happened, I had forgotten I had a daughter. That utterly terrified me. And then I couldn't remember the name of my hometown, the place where I grew up. It's Barnsley, by the way; I looked it up. More recently, it's the headaches, migraines that feel like someone has my head in a vice. That's when I retreat into the darkness. That's when the thoughts invade like a snake wrapping itself around my neck and whispering poisonous lies into my ears, making me doubt myself and my life.

Dan and I both knew what all the symptoms meant; we both recognised the signs of dementia. Unfortunately, we know about it all too well because my dad was diagnosed with Alzheimer's in 2018. It was Dan who joined the dots on Dad's symptoms first. Being a professor at the London College of Neurology has its twisted perks, I guess. And now it might be happening again. To me. I'm a scientist too - well, I was before, but it's hard to know who I am now without the data, evidence and facts to guide me through each day. Critical thinking and problem-solving were fundamental to my identity, but now basic strands of thought are becoming hard to grasp, and I feel spent and spare. Early retirement does that to a person, I think. I mean, I'm not even fifty yet, but I just had to stop. And let's be honest, I definitely ended on a high. When I look back at what I've achieved, I feel proud. I did something significant. But there's a whole second act to figure out now, and maybe I'm about to pay the ultimate price for the intensity of the first.

I had worked on a prototype gene therapy to combat Ebola back in 2013 during an outbreak in West Africa, but it wasn't cleared for use in a population. And then, well, epidemics die out naturally, and the research money suddenly disappeared. The pharmaceutical industry is a fickle master. But when the disease reared its ugly head again in 2018, we were ready to put our work into action, and that's exactly what me and my team at Oxford University did. I didn't expect the Nobel Prize. I didn't feel that I had done anything monumental like Alexander Fleming or Marie Curie; those who place the stepping stones ahead of us so that we can all tread the path. So, when it happened, I found it embarrassing, especially as it was a team effort and I was being singled out. That's why I declined the invitation to the Nobel awards ceremony in Stockholm.

I'm not one for publicity, and I hate fuss; it was all too much. I was very happy to deliver lectures, write my thesis and be a published scientist, but that's my limit, and all I wanted to do at the end of it all was take a break. Many of my colleagues couldn't understand it; I don't think Daniel could either. As well as the pound signs, I think they view a Nobel Prize in Physiology or Medicine like an Oscar for science: a doorway to fame, fortune and a lifetime of public speaking, standing ovations and whatever else your heart desires. To be honest, I just felt burned out, and all I wanted to do was read thrillers, plant daffodil bulbs and bake cakes with Maddie for my dad.

When I was finally released from my work, and the care homes opened their doors after Covid, I'd been absent for two years, and Dad didn't know who I was. I can't begin to tell you how devastating that felt.

Mum passed away a few years ago, and soon after, we realised Dad wasn't coping living on his own. The melted Tupperware on the electric stove that had nearly set the house on fire, along with the junk hoarding and the newspapers we found in the freezer, were pretty strong indicators he needed full-time care. We found him a place we could afford near to us: a home from home in the Home Counties. To my amusement, Dad didn't really fit in. He expected a full English with bread fried in an inch of bacon fat for breakfast. Instead, he got muesli and oat milk. Try putting that down in front of a Barnsley FC supporter and Premier Foods middle management retiree and watch it fly. He sounded off. Walking into Hartford Gardens over a year after we had last set eyes on each other, I was desperate to feel my dad's arms around me again. But in that moment when he looked up at me after that long-awaited hug, stared at me intently for a second and said, 'You're new here, aren't you?', I shattered. He didn't recognise me.

When you are consumed with work, 'family' sometimes feels like background music; something you collapse into at Christmas and Easter, or the occasional birthday barbecue. It grounds you and allows you to exhale a little. When I woke up after lockdown, all that had gone. I'd lived through it efficiently, working hard, relocating Dad, saying goodbye to the house I grew up in, but actually, stopping for that big breath was a shock. I couldn't open my eyes wide enough for what they needed to see because so much had fallen out of view, lost forever. My mum, my childhood and my whole life were held in my dad's memories.

I panicked. How the hell could I salvage what was slipping through my fingers? I know many other people have had to go through the same thing, watching the cruel decline of the people they love, so I'm not going to wallow in self-pity. But I decided something there and then. I decided to make more memories with Maddie and Dan. Then I would take those stories to Dad, planting new seeds in the hope that the roots would grip memories from his past and haul them up to the surface and into daylight again. But perhaps now I need to make memories for another reason. If the worst is true, I don't want Maddie to forget me, to forget who I was.

The MRI machine decelerates, and I exhale. The ordeal is over. I peel my naked backside from the slab and roll off. I'm starting to dress when Karima breezes in, all positive energy.

'We'll get these results to you quickly, Sarah, don't worry. I'm going to change your current prescription for the headaches. This one isn't a painkiller but an enzyme blocker. Works slightly differently. They should keep you a bit more balanced, but they can sometimes be a bit "buzzy".'

'Sounds...