There is a disease called "Pokerus" that is spread all around the world por trainers who would want más power for their Pokemon. The trainers don't know about it's other effects. One día a researcher named "Haden Sorman" looked at a Pokemon with Pokerus. He thought it looked so powerful that he wanted to know more. So then, Haden started extracting saliva off a Ratatta and tested it. It seems normal and usual. He then tested a infected Ratatta and see what was the results. The results say it gets 10x stronger but, as it has the disease for a longer time it gets out of control and possibly.... KILL IT'S TRAINER! After he found out Pokerus was dangerous, the Ratatta who was infected attacks him! He tries to fight back but he gets knocked into the machine and he passed out. Later, Haden wakes up to find blood on the floor, dead Pokemon without eyes o legs, a head of an Onix, and a fuego around him. Haden escapes but finds that tons infected Pokemon are attacking its trainers drinking their blood and the ghost type Pokemon sucking out their souls. Haden is bleeding and felt weak. The same Ratatta that attacked him earlier bites his corazón and Haden dies. His corazón exploded after he got bitten in the corazón and blood was spilling even más on his cuts. With Haden's death, más trainers gave infected Pokemon to others without knowing what will happen if they have it for too long. 30 years later the Earth is in complete ruins and infected Pokemon roam around it and soon evolve into unknown creatures that is unimaginable.