Cloud must face Sephiroth again to stop a disease called Geostigma from spreading. Geostigma is infecting children and drawing them to Sephiroth. It causes symptoms and is connected to Sephiroth's remnants. Cloud and his friends, the original heroes who defeated Sephiroth before, work to understand Cloud's connection to Sephiroth and Jenova and stop the threat in the city of Midgar, where most people live.