During this 30-minute special retrospective, series stars Johnny Galecki and Kaley Cuoco take viewers behind the scenes of the longest-running multi-camera comedy series in television history.In the special, Galecki and Cuoco will lead fans on a trip down memory lane, sharing some of the best-kept backstage secrets and personal memories from the past 12 years. They will reveal their favorite moments playing beloved characters Leonard and Penny, and revisit some of the most memorable stories from "The Big Bang Theory Stage." In addition, the special will feature a tour of the iconic sets, including Leonard and Sheldon's apartment.