There I was, minding my own business on the tube journey home.
It was Bank Holiday Monday, and like most Britons, I was grateful to be out of the offensive blizzard blown by Storm Katie.
Even better, I'd managed to source a seat on one of the Northern Line’s relatively packed middle carriages.
Opposite me sat a Middle Eastern man. We made eye contact. Then, I whipped out my iPad, plugged in my headphones, and continued watching a pre-downloaded BBC documentary.
As the train passed through Hampstead tube station towards Golders Green, I looked up. Aside from one other woman, it was just the two of us sitting on the right hand side of the carriage. Everyone else seemed dispersed to the left.
He was looking at me again, but this time, his watery eyes were clouded over.
He was painfully slumped in his seat, almost falling off. He started to slowly unzip his black jacket, revealing two pieces of black string that he clutched on to. His face was covered with beads of sweat. He looked left, then right. Left, then right again. He started gasping. He looked awful.
No one else seemed to notice; their heads firmly fixed on their papers, magazines and iPhones. I couldn’t catch anyone’s eye.
Fixated on the suspicious strings hanging around his midriff, truly, I thought something terrible was about to happen – and I don’t consider myself to be an irrational or easily panicked person.
Still travelling along through the six-minute (excruciatingly long) dark tunnel, there was really no escape. Running to one side of the carriage would hardly have made a difference - not to my mind at least.
So what was I to do? I stood up and walked over to him.
“Are you okay?” I asked. “Can I help?”
He shook his head and said: “I can’t do it.”
They were not words I wanted to hear.
“Can’t do what?” I asked, telling him to wait until we stopped at the platform, where he could be helped. He clutched his stomach.
“It’s my tummy,” he said, almost childlike.
Useless, I laid some tissues beside him. I considered pulling the emergency lever, but who in their right mind would want to get stuck in a tunnel at that point?
And still, no one, except the woman to my left, looked up. She had however, edged away towards the other end of the carriage. Her large brown eyes growing larger still.
Then, he keeled over and vomited a powerful spray of red fluid across most of the carriage.
I have never been more relieved to see someone throw-up, I’m a little ashamed to say.
As we pulled into Golders Green station, I suggested he come outside for fresh air. He vomited again.
I stepped out of the carriage to see if someone on the platform could help. No one. Then, the familiar TfL beeping started, and the doors shut. The train left the station, taking the poorly man with it.
I felt guilty. Guilty for not helping him more, and more so for having suspected the worst of him – for having suspected an imminent attack, like the one in Brussels, or Paris or London back in 2005.
I pulled out my phone and arranged to meet a friend. My hands were shaking and my body had gone ice cold.
I was not getting back on the train that day.
Religious and political leaders have told us to fight terror with “hope”. To have no “fear”. But therein lies the true power of the terrorists. They’ve sparked a wave of fear no matter how defiant and brave we try to be. And of course, they’ve created division. One person looking at the other with suspicion on flights, in packed shopping centres, and yes, across train carriages.
I considered not writing anything about this incident – “why talk about fear?” one friend said. “That’s what they want, don’t give them attention. Don’t write about it.”
Though I don’t consider myself to be a particularly sensitive or delicate person, for the past two nights since the incident I’ve woken up in the early hours with a fright. In both nightmares, the worst situation came to pass.
And in the wake of the repeated, unsurprising, terror attacks, alerts and warnings, I wonder how many other people across Europe have started to feel the same?