Probability Calculus

I ran up the stairs, instinctively scanning the letters I'd just taken out of the mailbox. I wasn't expecting any revelations. Most of them were advertisements, one letter had a stamp from the energy office. I have to pay my electricity bill again. At the very bottom was a gray envelope. My heart started pounding. I felt… fear? I stopped in my tracks. I was terrified of the letter… I didn't even know who it was from. My address was typed on the computer, as if it were another official letter, but there was no stamp. I examined both sides of the envelope – there was no information about the sender.

I finally moved, laughing to myself. My grandmother, and probably my mother too, would say I just had a bad feeling. But a PhD student in mathematics, researching the probability of prime numbers appearing in number games, that is, me, couldn't take such nonsense seriously. Belief in so-called I'd long ago put my premonitions, along with my fear of witches, on the shelf.

When I entered the apartment, I deliberately put all my correspondence aside. It could wait until evening. There's nothing interesting there, after all.

It took me half an hour to prepare dinner [peeling potatoes for fries and preparing a salad]. Then I busied myself with sorting the dirty laundry. Then I watered the plants. When I started arranging the books on the shelves, I realized I was behaving differently than usual. Usually, the first thing I did after arriving home was light the kettle. And so I spent a relaxing fifteen or half hour with the newspaper, a book, or correspondence.

I sat down in the armchair. What was happening to me? I glanced at the pile of papers lying by the lamp. I had to start behaving rationally. I got up and calmly approached the table. I didn't waste time searching for a knife; with a decisive movement, I tore open the gray envelope. A plain white piece of paper fell out. When I unfolded it, I discovered only a few words were printed on it: "Beware of Rumcajsa," and below them was the address of some website. And that was what made my heart race. It's a good thing I'm a rational person, otherwise I'd be pacing around that envelope until the evening, anticipating who knows what.

Reassured, I returned to my daily routine. The text was admittedly odd, but I guessed it was one of my students playing a rather unfunny joke on me, because I sometimes give them a hard time.

The next day, I told the whole story to Monika, a colleague from the same department. Sometimes it was hard for me to believe we were studying the same subject, because her precise, mathematical mind allowed for belief in horoscopes, miraculous healings, and various other improbable things. As she herself said, her interest in mathematics began with a fascination with the magic of numbers. I liked her very much, but we often had discussions about empirical and irrational understanding of the world. The story of the envelope was supposed to be an argument in my favor. It's not worth believing in internal tremors, heartbeats defined as premonitions, because they have nothing to do with reality.

Monika not only rejected my arguments but was also very concerned. I had to repeat everything to her several times, and above all, describe how I felt at the time. She couldn't understand that I hadn't even checked the website she'd given. When I assured her it was definitely one of the students, she just nodded doubtfully. Finally, to calm her down, I showed her the page, as I'd accidentally had it in my bag.

I thought the matter was over, but when I entered our room after class, Monika jumped out of her chair and, genuinely frightened, dragged me to the computer. Of course, she'd found the page. There was my name, surname, the familiar words "Beware of Rumcajsa," and my phone number. All against a dark navy blue background. In the upper left corner was a tarot card with the symbol of death, and in the right, a photo of a woman in loose robes, her eyes heavily outlined with black eyeliner and the signature: Fortune Teller Selene.

I looked at Monika. I didn't understand her terror. After all, the matter had finally been resolved. Selene wants to make money, so she sends people messages; the website is supposed to convince them that they are in danger, certainly death. People call the fortune teller, and she tells them long and fanciful stories so that the phone bill increases accordingly. I nodded, because the matter seemed clear to me.

"I called them," Monika whispered. "I knew you wouldn't want to."

I thanked her for her concern and promised to refund the bill. She didn't let me speak for long, though.

"She's not a con artist. Yes, she makes a living from it, but She's telling the truth! You can't come home before midnight tonight, or something very bad will happen to you.

I asked if Rumcajs and Cypisek would be waiting for me outside the house. I wanted to lighten the mood, because Monika was clearly worried.

"Listen, she knew I was going to call and she knew I wasn't you. And besides, don't you wonder how she got your address?"

This didn't surprise me. It's true that data protection existed, but if it worked properly, I wouldn't be receiving so many ads every day. Monika, however, couldn't be convinced. I had to promise her we'd spend the evening together. I suggested going to the cinema, because they certainly didn't play cartoons about Rumcajs in the evening. My comment, however, didn't amuse her.

I didn't return home until the following evening. After the cinema, I found that my last bus had left. I could have taken a taxi, but Monika insisted I spend the night at her place because the taxi might arrive too early, before midnight. In the morning, we went to classes. When I got home, I breathed a sigh of relief. I didn't have any "premonitions"; I performed everything in routine order. Nothing happened to me, and Monika calmed down.

That evening, as usual, I turned on the TV to write down the lottery numbers that had been drawn that day, as I needed them for my research. While waiting for the drawing, I flipped through the channels. I came across "Dziennik." The woman in the dark green suit, looking me straight in the eye, announced that a member of a gang near Warsaw, Krzysztof L., also known as Rumcajs, had been arrested the previous evening. He had half a kilogram of drugs and a firearm on him. He was apprehended after a chase. The bandit tried to escape by car, then barricaded himself in a Warsaw apartment building and fired several shots at the officers. Fortunately, no one was injured. I sat and simply stared at the TV.

And at my apartment building, which they were showing. Could I really have been injured or killed by the gangster "Rumcajs" yesterday? Would I have taken out the trash, or maybe I would have had a craving for some blue cheese from the nearby store. No, that's too unlikely. On the other hand, what's the probability that only prime numbers will be drawn in a single draw?... Relatively high.

And tomorrow I'll call Selene. I should thank her. And maybe we can talk some more.