You're just any other male white blood cell in your home, the city of (whatever name you choose). However, one thing led to another and you find yourself flung from your home and into the body of your host's crush, Christine Kolchuck.

Finally landing, you find yourself in a large metropolis like your own, a sign hovering above reading "Welcome to Christine". Before you get your bearings, several cruisers driver up to you as several female white blood cells come out, hands to their belts. One of them, wearing a chief's badge, addresses you.

Hold it there, intruder! Who ARE you?....