What is a synopsis for always sunny season four?

The fourth season of "It's Always Sunny in Philadelphia" continues to follow the antics of five friends, known as "The Gang," who run an unsuccessful Irish bar in South Philadelphia. In this season, the gang attempts to solve their financial troubles by starting a drug cartel, opens a gay bar, starts a successful "Mercury Theatre" style theater company, and goes on a road trip to the Grand Canyon. Throughout the season, the gang’s schemes often go awry due to their incompetence, selfishness, and lack of ethics.