It's Always Sunny in Philadelphia - Episode 8.03 - 8.04 - Title and Synopsis

Episode 8.03 – “Maureen Ponderosa’s Wedding Massacre” (Airs October 25, 10:00 pm e/p) – Dennis and the gang crash Maureen's wedding to make certain he'll be able to sever all ties, only to discover a union much scarier than kissing cousins. Written by Charlie Day & Glenn Howerton & Rob McElhenney; directed by Richie Keen.

Episode 8.04 – “Charlie’s Mom Has Cancer” (Airs November 1, 2012 10:00 pm e/p) - In perhaps the most depraved scheme of them all, The Gang rallies around Charlie's mom as she battles cancer. As Mac, Charlie, and Dee struggle with their faith, Frank loses his memory and his mind in a quest for buried treasure, and they're all rocked by a revelation that will shake Paddy's to its very foundation! Written by Scott Marder & Rob Rosell; directed by Richie Keen.

Source: FX