User blog comment:Rafe Adler/Major Crossover/@comment-3423279-20160519143054/@comment-3423279-20160519143854

TBH all it would entail is Sam or Dean going to Earth Two, pushing the equivalent of a tnt lever on the Earth itself and then leaving after justifying to themselves "I did it to save your life brother, one life versus 7 billions is a fair trade" and then leaving.