Overview:
Your name is (whatever you choose) living with your nearing middle-aged mother in a nice home and enjoying a quaint middle-class lifestyle. Suddenly an unexpected worldwide epidemic has occurred, it's spreading at an alarming rate and most governments are having difficulty controlling the spreading of an abnormal parasitic disease.
It's primary transmission and evolution occurred with sexual intercourse via changing the infected brain's hormonal and behavior inhibitions.
With no super-ego or control of your morality to rely upon, things can get nasty... You the protagonist will endure many challenges, deciding upon regaining your super-ego? Or are you willing to go down the primal id path like so many others before you?
The affects it has on your life; as those around you will become evident as the game progresses.
So yes, expect things to get worse...