"The Splendid Source" is the 19th episode of the eighth season of the animated comedy series Family Guy. Directed by Brian Iles and written by Mark Hentemann, the episode originally aired on Fox in the United States on May 16, 2010. The episode follows Peter, Joe and Quagmire as they set out on a journey to find the ultimate source of all the world's dirty jokes. Along the way, the group is reunited with their old friend, Cleveland Brown, while traveling through Stoolbend, Virginia. Their journey becomes much more difficult than expected when they are kidnapped and taken to a remote island. There, they discover a secret society of the world's greatest geniuses at the center of all the world's dirty jokes. The plot is based on a short story of the same name written by Richard Matheson and first published in the May 1956 edition of Playboy magazine.

The episode was a follow-up to the departure of main character Cleveland Brown, who was removed from Family Guy to become the center of the spin-off The Cleveland Show. Former series writer and cast member Mike Henry returned to the series to provide the voice of Cleveland. The episode also featured the first official crossover between Family Guy and The Cleveland Show, and included cameo appearances by several of The Cleveland Show's main characters. The episode was first announced at the 2009 San Diego Comic-Con International.

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