I'd like for them to have one conversation prior to interacting with the shifters i.e. dean or sam talks with karen after realizing it is the karen from the police report. I can see her getting mad at them, b/c they'd be faking FBI and she's not happy with police right now. So she storms off, her and Lucille decide they are going to distract the shifters at that point. The guy comes into the room to look at the pipes, Lucille is not there, he and the female shifter take Karen. Lucille is looking up the information, because the female shifter wasn't in the office, sees that it's the same room, runs to tell Karen, Karen's missing. She decides to tell the guys, but sees shifter!dean or shifter!sam coming out of the office area, confronts him.....and then....i don't know....that's my idea so far.