There's always a method to the gang's madness on the FX original series "It's Always Sunny in Philadelphia." The Season 8 premiere, "Pop-Pop: The Final Solution" finds Dennis (Glenn Howerton) and Dee Reynolds (Kaitlin Olson) struggling with the imminent death of their maternal grandfather, Pop-Pop.
Frank, who has been caring for the elderly man, leads the gang to his hospital room, but it's a smelly, dark disaster. Frank admits that he has been feeding Pop-Pop soup, but if he doesn't finish it, Frank leaves the containers close at hand. Unfortunately, there are several months of rotting soup bowls stacked up on the bedside tables.
The former businessman's motivations aren't entirely benevolent, though. Pop-Pop reportedly has some Nazi treasure stashed away, and Frank wants his piece of that pie. While eating some of the ancient, congealed soups, Charlie (Charlie Day) remembers a box of memorabilia that came from the ex-Nazi. In particular, Charlie recalls a painting of a German Shepherd, which could be an Adolph Hitler original.
The search for that painting leads Charlie and Mac (Rob McElhenney) to the dog pound and Cricket (David Hornsby), who points them toward a dentist's office. Mac thinks Charlie is a pain and leaves him to the tender mercies of the dentist. Charlie does acquire the missing painting -- and a shiny set of unneeded braces to boot.
At Pop-Pop's apartment, Dennis and Dee find home movies of themselves, including one that shows their summer adventure at Camp Pakuna. Their grandfather had arranged their stay, but the camp turns out to be a thinly veiled Nazi youth camp.
After seeing the film, Dennis and Dee are ready to pull the plug, but Frank encourages them to try euthanasia on a smaller scale. The siblings visit Cricket at the pound, and he volunteers to let them watch a canine execution. Dee and Dennis realize they aren't killers, and instead adopt a bunch of dogs and set them free.
The attorney (Brian Unger) volunteers to pull the plug on Pop-Pop, but the former Nazi refuses to die. By episode's end, Charlie admits that he painted the artwork, which is driving everyone nuts. As he burns the painting, Charlie also says he actually painted over a painting that came from Pop-Pop. Before the final credits, Adolph Hitler's signature is clearly seen through the flames.