The gang has to deal with a case of mistaken identity on It's Always Sunny in Philadelphia. "Frank's Back in Business" is the seventh episode of the show's eighth season.
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It's Always Sunny in Philadelphia Season 8 Episode 7 Quotes

Mac: Fight Milk! The first alcoholic dairy based protein drink for bodyguards!
Charlie: By bodyguards! I drink it every morning so I can fight like a crow.

Andrew Caine: And you are?
Mac: Vic Vinegar. Bodyguard. I don't shake hands, so don't even try.