What do you do when the power goes off?

Terrorists have acquired a terrible new weapon that can crash the power grid and plunge America into a new dark age. A coordinated attack is planned to shut out all lights and emergency services to ten major cities. Planes will fall, hospitals will go dark, no help will come.

And in that terrible darkness, a dreadful plague will be released. If the lights go off, nothing can stop the bioweapon from killing millions.