The premise is that the Peanuts gang are in high school. The names are slightly changed, though easily recognizable, presumably to avoid legal issues. In the opening scene, C.B. is writing to his pen pal, setting up the situation. In short, his life has taken some strange turns ever since his dog died. His sister is a Wiccan, though she had been a fundamentalist Baptist not long before. She's also creating a theatrical piece about a caterpillar that wants to evolve into a platypus, providing some of the funniest moments of the play. His best friend, Van, is a pothead (and smoked the ashes of his blanket after his sister and C.B. burned it). Matt is a neat freak who hates being reminded of his childhood predilection for dirt, which had led him to having been called "Pigpen." Tricia and Marcy party and get drunk at school, Van's sister is on a locked ward for having set the little red-headed girl's hair on fire. And then there's Beethoven, who has been rejected ever since his father was arrested for molesting him. C.B.'s philosophical musings on his dog's death lead him to re-explore his relationship with Beethoven, triggering complex reactions from the other children.
Much of this is very funny, but there are serious undertones, with issues touched upon including drugs, sexuality, violence, and teen suicide. There's a hopeful ending, with a reply from C.B.'s pen pal. It's worth seeing, both for the parody and the reflection on what might become of familiar characters.
As for the performances, all of them were at least competent. I was particularly impressed with Keith J. Miller as Beethoven and Allison S. Galen as C. B.'s Sister.
I'll also note that this show made me more likely to see others done by The Little Theatre of Alexandria. In particular, they're doing The Visit, one of my favorite plays of all time, this fall.