As the bus drew to a halt and the doors swung open, none of the waiting passengers made to board. It had been the same at the last few stops. Nodding resignedly, the driver pulled away, likely knowing he’d have the same problem at the next stop. And the next stop. And the one after that. There were plenty of empty seats, but the bus may as well have been standing room only. People were afraid of one another. They didn’t want to catch the sickness by sitting next to another passenger.

I knew that this was nonsense, as they should, but despite countless advertising campaigns debunking the myth that the Itch was contagious, the lasting effects of the hysteria caused by the sickness were still present. Professionals never greeted with a handshake. Reunited friends never hugged, no matter how long they'd been apart. Having witnessed the symptoms of the Itch, I could understand the stigma, even if I didn't share in it.

I left the bus just after crossing the river on Bridge Street. As I got off the bus, one of the five people waiting dashed on, which was frustrating for those who'd missed a seat. From there, I headed to Spinningfields. I used to like the area – old redbrick architecture merging with modern towers of glass and steel – but it had changed a lot in recent months.

Before the Itch, a lot of the buildings in Spinningfields were offices or restaurants. To cope with the rising number of patients, the government had started converting available space into hospital wards. Concert venues, offices, and conference centres had all been given a medical makeover. Nowadays, every other building was being used to treat the sick. The temporary signs placed at entrances to these makeshift hospitals were looking worn, which was a damning sight. It seemed like the only buildings spared the transformation were those already dedicated to combating the Itch, one of which was my employer, Rathbury-Holmes.

The company specialised in pharmaceuticals. Their laboratory was nestled amongst the other blocks rising above Hardmann Square. It was vastly different at night. The mob that had been occupying the paved square for months now had disbanded for the evening. There was no point campaigning if there was no one to listen. Even so, I could hear their abuse ringing in my ears. That was the main reason I was there; somebody had to find out what had happened.

The guard behind the front desk gave me a puzzled look as I approached. Determined not to give myself away, I kept my face impassive.

“How come you’re here so late?” he said, checking the monitor in front of him.

“Frank asked me to come in to sort some stuff. Call him if you want?” I said, nodding towards the phone. The guard thought for barely more than a blink before shaking his head softly.

"I'd rather not," he replied. Frank – my boss – had a formidable temper, and the guard clearly knew that he wouldn't appreciate being bothered in the evening.

I’d received the full brunt of his rage earlier that day. A halfway decent manager would have handled this situation very differently. I was still struggling to believe that he’d asked us to drop the investigation. How could I? Seven people were dead. And I was determined to find out why.

As I rode the lift to the fifth floor, I reached for the necklace I was wearing. It was only simple – a piece of string with two bottle caps hanging from it – but it meant more to me than anything else. If anyone had known why I wore it, they might have thought it was nothing more than a painful reminder. I didn't think of it like that, though. To me, it was motivation.

I left the office lights off, keen to draw as little attention as possible. My desk was exactly as I'd left it earlier, speckled with stationery and paper that I'd scattered in anger. Frank's office was on the other side of the room. Someone was moving around inside, so I tucked myself behind a pillar and waited for them to leave. Initially, I was worried it might be him but realised it was probably one of the cleaners finishing up for the evening. In all the years I'd worked for him, I couldn't think of a single instance when Frank had stayed a minute later than he had to. Plus, the person in there was much too slim.

Once the sound of footsteps had faded, I peered from behind the pillar. I was alone. Eager not to waste any more time, I dashed over to Frank’s office. Of course, the door was locked, but I’d expected as much. After a few seconds, I found a video on the internet that explained how to use the lockpick I’d bought online. It took several attempts, and at one point I was sure I’d jammed the lock, but the door eventually swung open.

As I entered, I vividly recalled our discussion from earlier.

“I told you to drop this,” Frank had yelled. His flabby cheeks were beetroot red, a combination of his anger and unhealthy eating habits.

“And I told you there was an issue before the trial."

“Are you suggesting this is my fault?”

“I never said that," I’d replied, although I certainly felt that it was Frank’s fault. After all, he’d approved the protocol, despite my warning.

“If you’d thought there was a real concern, you should have-”

"A real concern? You saw the data. You knew what the risks were. And yet, you pushed the trial. We were supposed to be helping those people. Now, seven of them are dead. Their blood is on your hands."

“Those people were dying anyway. They’ve only themselves to blame,” he’d roared.

In my frustration, I said a lot of things that I probably shouldn’t have. Worse, though, was the volume with which I’d spoken. Everyone in the office must have heard my tirade. But I didn’t care. He deserved what I’d said and worse. How could he be so callous? True, those people were in a critical condition, but that certainly didn’t make their lives expendable.

I’d considered going to a news agency, or perhaps plastering what Frank had said all over social media. But in those scenarios, other people at the company might suffer; people who’d worked on the project but didn’t deserve to be punished. I wouldn’t let that happen, just as much as I wouldn’t let Frank get away with what he’d done. So, I’d decided to sneak into his office and look for anything that might explain why he’d pushed the trial.

His desk was clinically tidy. Everything was either perpendicular or parallel to everything else. It seemed strange that someone could be so careful with office stationery, but so careless with people’s lives. Slowly, I moved a photograph of his gigantic Rottweiler, taking note of how it aligned with everything else, and then flipped his keyboard – just as Frank did every morning. Sure enough, his password was taped to the underside.

Arranging his emails into date order, I scrolled to roughly three months ago, which was around the time I'd first voiced my concerns about the trial. Annoyingly, he hadn't opened any of the messages I'd sent him. That was enough to land him in serious trouble – they proved he'd ignored my warning – but I wanted more. I wanted to know why he'd knowingly endangered the patient's lives and, ultimately, killed seven people.

I was busily scrolling down the list of emails, but something beneath the desk was making it difficult to sit comfortably. Irritably, I reached under and pulled out a small duffel bag. The zip was open, revealing a small digital timer. It was counting down, seconds away from zero.