What just happened

China has released a chemical in all state owned water cleaning centers. The result is a mixture of fear, anger and acceptance. The chemical that was released transforms some people into different fantasy races. Everyone reacts differently with the substance. China claims that the chemical is harmless but the damage has been done. In response the USA launches a nuke on the capital of china. The result is a five day long war between all nuclear powers on the earth. The soviet era nukes is little to no help for Russia, the old war heads crash down on everyone unfortunate to be in the way. Approximately 100 - 90% of all war heads are used in the war, the earth is laced with a nuclear winter. All power plants have either been destroyed in the 5 day war or are about to give in and poison the soil it stands on. The state of the world is unknown, all you know is that the world you once knew is all gone. Maybe some country far, far south survived. Luckily you got into a big underground metro system. A few people you know are there too. And for the outside, and soon some parts of the underworld, well - new creatures has emerged as a result of when the chemical reacts with a creature in a radioactive environment.