9. The Prestidigitation Approximation
Season 4, Episode 18
Title Reference: Howard's sleight of hand magic trick, which he uses to trick Sheldon. Priya asks Leonard to stop hanging out with Penny. Meanwhile, Howard shows Raj and Sheldon a magic trick, much to Sheldon's annoyance as he can't figure out how it was done. Sheldon spends his time trying to work out how to do the magic trick, including using infra-red cameras, super-computers and barcode readers. All to no avail.
Best Moment: Howard repeatedly tricks Sheldon with a card trick, to Sheldon's annoyance.