If you want to see theater in one of its most nerve-racking forms, look no further than actor Colin Mochrie. The comedian is best known for his role on "Whose Line Is It Anyway?," a popular short-form improvisational comedy show. Mochrie has a richly deserved reputation for his skill at improvisation. Audiences in Atlanta can see him live on Aug. 11-12 at Dad’s Garage in Atlanta. We talked with him about his craft.