After Pai Has Calculated Everything

π, the origin of all things. Only after humanity discovers π do people realize that this world can actually be simulated! People exhaust every means to calculate π. The more precisely they calculate it, the rounder the circles they draw become. But once humanity calculates all of π, they discover that our world was already determined. All our past experiences, everything that ever happened, were merely projections of π as it became more precise! Oh my God! I'm not even myself! We are just simulations of the digits in π. After that, people stop working, getting married and having children, spending money on medical care, and talking to one another. Everything they do is predestined. Our lives, oh! No, our programs are predestined! People sink into apathy. But much later, we discover that this is merely a way for other life forms to invade our world. π has not been fully calculated! Our world still has hope! But the further we calculate, the more we discover that the invasion by alien life is also hidden in the digits of π! Physics collapses, the economy plunges into depression, and mathematics falls apart! For humanity! Our armies keep sending interstellar fleets to other star systems. Could it be? They see the armies of Qin Shi Huang fighting in Saint Petersburg! They see humanity's past! They see humanity's timeline! The closer they get to the end of time, the more their ships, their weapons, their clothes, their fingers, and even their bodies slowly vanish...