Journalist: "Well yes, but one thing is obvious: this might open a real can of beans."
Eminent pundit: "Err, yes, a can of beans, indeed…"

[Pause] Suddenly not so stern-sounding journalist: "Oh dear, did I say can of beans? I meant can of worms, of course."[Laughter] The Today Programme, on Radio 4, early in the morning.
Once I had stopped chuckling to myself, my mind turned, as it usually does, to the translation of this particular term (can of worms, rather than can of beans). I know that to open a can of worms means that you discover a source of unforeseen and troublesome complexity, the dozens of mixed-up worms seemingly impossible to untangle. In French, I can’t think of an equivalent expression. Word reference gives guêpier (wasps’ nest) as a translation, but a guêpier it is more of a trap, a problematic situation difficult to get out of: to land oneself in it would be a good equivalent of se fourrer dans un guêpier. It doesn’t convey the idea of unexpected complexity, problems bringing on more problems. The expression un sac de nœuds (a bag of knots) conveys a similar image of entanglement, but not the idea of surprise. So I’m left wondering. If you can think of a good translation, I shall be very grateful.