It's a Mystery, Charlie Brown is the 11th prime-time animated television special based upon the comic strip Peanuts, by Charles M. Schulz.

[1] This was the first Charlie Brown television special that Bill Melendez did not direct, but he still served as producer and provided the voices of Snoopy and Woodstock.

They all go to see Lucy in her psychiatric booth, which she temporarily converts to a courtroom enlisting Linus as stenographer, and she tacks two cents on to her normal five-cent fee to cover court costs and asks they pay in advance rather than after.

The two sides present their case to Judge Lucy: Snoopy, as Woodstock's attorney, with a document containing excessive legal jargon, and Sally with "Finders keepers, losers weepers".

Stenographer Linus is not much help as he can only remember a few words said before the case was fully announced, but Lucy rules in favor of Woodstock, saying that since he built the nest, he should keep it.

The Paramount release is notable for fixing an animation error where Charlie Brown, Sally, and Snoopy are shown in mid-air by zooming in the footage