When the virus started it went unnoticed to the average civilian. Coming across like the common cold that with the right amount of Cold medicine you will be fine. Of course something darker was hidden within this virus, that after a few weeks it develops.
You will play as a character wakes up to your normal job at the hospital only to find things won't be like every other day.
You are not logged in.
If you log in before playing, you'll be able to save your progress - which means you can come back later and pick up where you left off.