It’s a Mystery, Charlie Brown is a 1974 animated television special and the eleventh entry in the Peanuts series. It is problematic, but has its strengths.
Snoopy and Woodstock go on a hunt for the missing nest. The premise itself had potential, but it was executed weakly. The whole first half with the checking of the places is really boring as most of those places and kids in it do not do anything memorable and they react in a forgettable manner. And Charlie Brown is underused here as well as most of the kids are.
But Woodstock is quite endearing and Snoopy is very funny at times. Of course, that whole court scene is really fun and it plays on the strengths of Lucy and Snoopy really well. Sally is naturally one of the highlights here as most of the lines she says are hilarious. And although I disliked the ending as it ended on an abrupt note, the whole second half is quite good with its fair share of charming sequences. But overall, this special is disappointing unfortunately.