Hey, Christopher, did you ever find the version of Monster Illusion from This Side of Paradise that you were looking for?
Oh yeah, I noticed that there was some of that "ping-ping-ping" at the beginning of that cue in "The Cage" after all. Although what I'm remembering could be the third-season library version (which means I'd be wrong to associate it with "This Side"), but I haven't gotten there yet. Or it could just be that I'm misremembering aspects of it. When you try to memorize a piece of music that you hear piecemeal under dialogue and sound effects, the brain does a certain amount of interpolation and guessing, so sometimes the version in my head isn't quite the same as the real thing.