glass onion

A glass onion is something that appears to offer layers of meaning or mystery but is actually transparent or empty at its core—you can see right through it.

The phrase gained currency from the 1968 Beatles song, which presented seemingly profound lyrics that were intentionally nonsensical.

More recently, the 2022 film *Glass Onion* used the image for a puzzle that looks complex but has an obvious solution.

The conspiracy theory turned out to be a glass onion—there was nothing there.