From bona fide movies stars like Charlize Theron and Ben Stiller to comedy icons like Julia Louis-Dreyfuss and Martin Short, Arrested Development has always featured plenty of celebrity guest stars. And while Season 5 Part 2 doesn't feature quite as many as it has in past seasons, what the most recent batch of episodes lacks in quantity, it more than makes up for in quality. The celebrity cameos in Arrested Development Season 5 Part 2 are few and far between, but they do fill in some crucial backstory for the Bluth family.
While most episodes of Arrested Development open with Ron Howard's voiceover, a few episodes of Season 5 Part 2 instead start out with a flashback, detailing a visit to the Bluth's beach house when Michael, Gob, Lucille, and Buster were just children. The flashbacks show Gob falling in love with magic for the first time during a pageant their parents forced them to compete in in order to earn their approval, with real-life married couple Cobie Smulders (How I Met Your Mother, The Avengers) and Taran Killam (Saturday Night Live) playing younger versions of Lucille and George Bluth, respectively. They're joined by Jean Smart of Designing Women and Legion as Mimi, Lucille's mother, who shows that the fruit does not fall far from the tree.
"But wait," the dedicated Arrested Development fan might be asking, "didn't Seth Rogen and Kristen Wiig play Lucille and George Sr. during a flashback in Season 4? Why would they make this change?" You'd be correct, but as Season 5 Part 2 eventually reveals, the flashback we're seeing is actually a show within a show. In the world of Arrested Development, there is a docu-series called Making A Monster about young Buster Bluth that stars the real-life Smulders, Killam, and Smart as members of the Bluth family — and it's produced by none other than Arrested Development's narrator, Ron Howard. That the three actors are playing themselves playing roles in a fictional show within a show is a meta twist fitting for Arrested Development, which has always played with its own self-awareness.
The flashback isn't just a fun joke, however, as it also proves to be a defining moment in the childhood of the Bluths — showing the death of their grandmother, as well as revealing the true identity of Lindsay's mother. As it is portrayed in Making A Monster, Lindsay was conceived during an affair between Lucille's mother Mimi and Stan Sitwell. Mimi abandoned her daughter, and when she later turned up at the beach house hoping to take Lucille on a cruise, the two got into a fight about who deserves to have a say over Lindsay's childhood. It was then that a young Buster got angry watching Mimi yell at Lucille and pushed her down the stairs.
So while Arrested Development didn't introduce many late-run guest stars in the second half of Season 5, they took the guests stars they had and made them part of one of the most surprising reveals of the entire series.