Professor of theoretical physics Walter Klauss from the University of Oxford had his office on the second floor of one of the main buildings of the university campus, which became a legend over time. Colleagues, graduates, and current students only knew three things about him: he has been teaching here for a long time, he has a cat at home, and with a cup of coffee in hand, he plays chess every Tuesday at half past five in the afternoon with whoever is nearby.

On Tuesday, November seventeenth, which happens to be the day this story begins, no such volunteer (or person who didn't have time to say no) was to be found. So, with a sigh, the professor had to unfold the chessboard himself, pour two mugs of coffee, and open the window with a picturesque view of the stone wall opposite.

Exactly five minutes later, a spotted cat was sitting on the windowsill, the kind you would definitely not have noticed, and which you must have met at least a million times in your life. Unless, of course, you live somewhere on a deserted island in the North Sea, or in the middle of an unexplored jungle. But this cat was special.

Perhaps any true cat lover would have noticed - she had pale spots around her eyes, and her eyes were an unusually bright shade of amber, but the real reason why this cat was special was only known to her and Professor Klauss.

The cat blinked twice, and as if it was the most normal thing in the world, spoke with complete calm: "We need to talk."