User blog comment:Tommy,Klaus&Kol2012+/How to Kill a Levithan/@comment-168.16.130.206-20120225194051

or maybe Crowley and his legions assist the brothers b/c the enemy you know is better than the one you don't. Also, Crowley has been largely absent, except for a couple episodes, maybe researching a way to help the Winchesters and restore the balance of power among the supernatural community(demons,angels, etc.). Alternatively, HallucinaLucifer could pester Sam into using his psychic abilities again to stop the Leviathans.