PlotSheldon struggles to do projects with Amy, Leonard, and Howard all on the same day. Bernadette goes back to work after her maternity leave ends.
- Two-Timer Date: Sheldon does a variation, going back and forth between Leonard and Howard with the guidance system and Amy with her research. He ends up getting sick and going on a cough syrup-fueled bender during which he loses a notebook with confidential information at a cowboy bar. Lampshaded by Penny.Penny: Aw, looks like someone invited two dates for nerd prom.
- What Did I Do Last Night?: Sheldon wakes up after taking cough medicine and finds that he's naked from the waist down, and has lost a notebook full of confidential information about the guidance system. He finds it at a cowboy bar, where he also told everyone there about the guidance system.