In Amsterdam, a man teases pigeons, throwing leaves like they are food and smirking as the pigeons chase after them, waiting for the birds to bite and taste nothing, as he has tasted nothing his entire life.
In Siena, a child is kicking an old loaf of bread across the piazza, aiming his foot so that the hard, stale bread strikes a pigeon with each kick. He is overheard yelling ‘I got it! I got it! Right in the head!’
We watch these people grow from pigeon-tormenting youths into pigeon-despising adults—or something worse—and become depressed.
But in a future world we see these people reincarnated as pigeons, and are then satisfied.
But, in an even farther future world, we see that the most advanced creatures living on the planet are, in fact, pigeons, and once again, become depressed.