This Week's 'It's Always Sunny in Philadelphia' gets a guest visit from Seann William Scott, who plays Mac's cousin Country Mac. It's a good fit, and he plays the better version of Mac.

The episode opens on "11:55 AM On a Saturday" where Mac is reading from the bible to the gang for the start of "Mac Day," in which everyone has to do what Mac wants. The gang are all wearing sleeveless shirts, and Mac has modeled the day on the Bible, specifically Genesis and the creation of the world in seven days, which leads everyone else to groan.

At Paddy's, the gang complain about the seven straight hours of lecturing (with five dedicated the sin of homosexuality) so far, and when Mac comes back he reads more from the bible, and tells them that they're doing a "Project Baddass" video with Mac's cousin Country Mac (Scott). The two are doppelgangers. Mac plots to jump off the Strawberry Mansion bridge into the water, but with his jump done as a post-effect animation. On the bridge Mac and Country Mac prepare for his fake jump while the rest of the gang show that they're terrible at acting when Country Mac jumps off the bridge and survives with his beer intact. The gang then think Country Mac is Badass, which upsets Mac. The movie on to a planetarium where Country Mac wants to incorporate day three (the creation of trees and stuff, which Mac skipped) into day four (the stars) by smoking a joint. Mac hates ceding control because he's trying to put the fear of God into the gang, but Country Mac sells them on God by talking about the good things about life (like French kissing) and gets everyone but Mac very high. The gang has fallen for Country Mac, and sing his praises while eating munchies, and then say that maybe it's that they don't like Mac.

The rest of the gang say good things about Country Mac, which annoys Mac, as they go into a bodybuilding competition where the plan is to grease up the bodybuilders. It's there that Country Mac reveals he's been getting phone numbers because he's out and proud. They then move on to a karate tournament, where Charlie, Dennis, Dee, and Frank sign up Mac for a black belt competition. Mac gets a point and then gets kicked in the face. Country Mac decides to brawl with Mac's competition which leads to people rushing in from the stands.

Leaving the tournament, Mac is happy with his black belt point, while everyone else sings Country Mac's praises and tells Mac that he got his butt kicked. A brawler comes over to fight, but Country Mac strips the man of his knife and sends him off, while Mac poops himself. Frank suggests they swap Macs. Country Mac takes their invitation to join their gang, and then drives off and falls off his bike. Cut to: Paddy's, where Country Mac's funeral is being held, and Mac says that Country Mac is in hell for his ways and then does karate poses. The day ends and it starts being "Frank day." First thing to do? Flush Country Mac's ashes down the toilet.

Wow, whatever happened between this season and last, it was good for the show, because 'It's Always' is on a run here, and this was another great episode with a number of big laughs. It played on the characters we know and said something about them, while also showing up Mac in the best possible way. If this season keeps going at this level, it could be their best season yet. The show has been on the air for a while, but something happened, and they're really cooking.