Sherri is in the City Bank of Milwaukee when Ronald Resnick holds everyone hostage in an attempt to prove that something inhuman is behind the robberies occurring in the city.
While locked in the bank vault, she waxes lyrical to Sam about Dean's attributes. At some point the shapeshifter takes on Sherri's form. Dean and Sam find Sherri's body, they drag Sherri in and accuse her of being the shapeshifter. She faints, and Dean is about to kill her when the corpse reveals itself to be the shapeshifter, attacks the boys and runs off. Dean eventually tracks it down and kills it.
The real Sherri is escorted from the building by the SWAT team.