|“|| Sam: We're not the bad guys, Dash.|
Dash: I beg to differ. You're wearing flannel.
— Dash to Sam and Dean
Dash arrives at the LaCroix mansion to attend the late Bunny's wake. When Sam and Dean pay the family a visit, Heddy introduces everyone, and refers to Dash as "the baby of the family" who's in "Harvard business". Dash asks how the brothers know Bunny and they explain that their surrogate father Bobby Singer did.
Later that day, Stanton ends up dead and Detective Howard decides to detain everyone in the lounge for questioning. Sam and Dean arrive to find Heddy arguing with Dash. Heddy believes Stanton's wife Amber is guilty, but Dash disagrees. Dash begins insulting Heddy based on her age, much to Heddy's disgust.
After the fight, Sam tells Dash his surprise that despite two deaths, the family seems fine. Dash informs Sam that the family doesn't really like each other, calling it a family secret. When Sam asks why he trusts Amber's innocence, Dash believes she is incapable of murder, citing her inability to use WiFi as proof. When Sam asks if Dash believes in Amber's story, Dash says he doesn't believe in ghosts because thinks Lance is the most likely candidate to come back haunting.
Once Detective Howard finishes interviewing Amber, he calls for Dash.
Sam and Dean eventually find out that a shapeshifter is among them. While Dean is looking around the Billiard room, he hears noises coming from the closet, and finds Dash and Amber kissing, which proves Heddy's accusation that Amber was cheating on her husband. However, both proclaim they did not commit murder. Dean insists they touch the silverware he brought to prove they aren't shifters: they pass.
When Detective Howard turns up dead, Heddy accuses Amber of murder again. To prove her innocence, Amber and Dash confess about their love affair, though this only causes both Heddy and her sister Beverly to point fingers at both of them. When Sam and Dean try to break up the fight, Dash aims the detective's gun on them and accuses them of murder, since they are the only thing different compared to previous family gatherings, which did not result in murder.
Dash locks Sam and Dean in a room. When Heddy questions their motive, Dash assumes Sam and Dean came for the family's inheritance. While he waits for the police to come and arrest the boys, he and his remaining family members are approached by Olivia the maid, who reveals herself to be Bunny's daughter that had been locked away in the attic. She soon reveals she was the murderer and attempts to kill everyone, but her plans are foiled by Sam and Dean.
Realizing his mistake, Dash apologizes to the brothers and wishes he could somehow repay them. Dean asks that Dash simply forgets they were ever here.