A thought is that the non-x-men go to the museum of natural history where someone releases [url=http://marvel.wikia.com/Mutant_Growth_Hormone]MGH[/url] and[url=http://marvel.wikia.com/Hypercortisone_D]kick[/url] to try and boost humans into a mutant outbreak with dozens of people unable to handle the new powers. Now you have the secondary characters getting a jump as well but at least something resembling training for most to help quell the chaos before it becomes a full scale riot.