In the season finale, Charlie gets the gang to help him put together a rock opera based on his song "Nightman."

Episode Viewers and Ratings

Season 4 Episode 13 of It's Always Sunny in Philadelphia resulted in a 0.00 rating in the 18-49 demographic.

It's Always Sunny in Philadelphia Season 4 Episodes...

• s04e01 - Mac and Dennis: Manhunters
• s04e02 - The Gang Solves the Gas Crisis
• s04e03 - America's Next Top Paddy's Billboard Model Contest
• s04e04 - Mac's Banging the Waitress
• s04e05 - Mac & Charlie Die (1)
• s04e06 - Mac & Charlie Die (2)
• s04e07 - Who Pooped the Bed?
• s04e08 - Paddy's Pub: The Worst Bar in Philadelphia
• s04e09 - Dennis Reynolds: An Erotic Life
• s04e10 - Sweet Dee Has a Heart Attack
• s04e11 - The Gang Cracks the Liberty Bell
• s04e12 - The Gang Gets Extreme: Home Makeover
• s04e13 - The Nightman Cometh

It's Always Sunny in Philadelphia Show Summary

Five egocentric friends who run a neighborhood Irish pub in Philadelphia try to find their way through the adult world of work and relationships.

Unfortunately, their warped views and precarious judgments often lead them to trouble, creating a myriad of uncomfortable situations that usually only get worse before they get better.