Undercover Economist

One of the privileges of being a parent is that you get to snuggle under a blanket with a couple of little goblins and watch “Labyrinth”, and pretend it’s a selfless act of good parenting rather than a shameless piece of self indulgence.
Watching the film again I noted it that it seems to have drawn inspiration from the magnificent Raymond Smullyan. Tomorrow, in Smullyan’s honour, I shall set you the hardest logic problem of all time. No googling the answer, please.