After opening with an unexpected (and unexpectedly horrific) bank-vault massacre perpetrated, apparently, by Our Intrepid Heroes, the episode leaps back to reveal what’s actually going on: Leviathan Chet — he of the especial fondness for convenience-store cheese — actually swiped a bit of Sam and Dean’s DNA from Last Week’s Motel Room, and two of his fellows have cloned themselves into the boys to embark upon a multi-state killing spree designed to bring the hammer of American justice down upon the real Sam and Dean’s heads. Yes, it’s an unnecessarily complicated scheme to get the guys out of their way when the Leviathans should just be shooting the Winchesters in the face with those fancy TEC-9s they’ve managed to procure for themselves, but it led to one of the most entertaining episodes this show’s produced in a very, very long time, so whatever.
With Bobby’s assistance — of course — the real Sam and Dean first attempt to mask their identities with the help of some master forger and all-around paranoid lunatic named Frank Devereaux, but eventually, they decide the only way to deal with the situation is to confront it head-on, because Sam and Dean are idiots. Well, actually, they decide to confront the situation head-on mainly because Fake Sam ‘N’ Dean manage to rack up an absolutely appalling body count in just a few short days, but I think we can all agree that Sam and Dean are idiots just the same. In any event, Sam plots out the Leviathans’ spree killings on a map of the United States, tracing them from Jericho through Black Water Ridge to Lake Manitoc and St. Louis to realize the Leviathans are hitting the very same towns Our Dear Boys did way back in Season One, and in the exact same order. So, they motor on over to Ankeny, Iowa, to head the Leviathans off at the pass, as it were, only to find themselves promptly arrested by the fantastically competent local constabulary while their Leviathanically enhanced doppelgangers look on with evil smiles on their faces. Fortunately for the real Sam and Dean, though, Bobby’s learned that borax quickly reduces Leviathans to clumps of charred and mangled flesh and, after they convince the Ankeny sheriff of the truth, the real Sam and Dean douse the fake Sam and Dean with various cleaning products before decapitating them. Problem solved, right?
Not quite. In a quick, end-of-episode scene between the lead Leviathan and Crowley, of all people, we learn that the Leviathans have infiltrated the highest levels of power in the United States, including several government agencies and some of the largest corporations. DUN! Now, watch as the idiots in charge of this mess drop this shocking development completely for the next five or six episodes so we can instead watch as Dreary El Deano tries to out-emo The Ginormomope again, some more.