One of the usual stripes of a mystery story is The Locked Room; the body turns up in a room that's sealed in some fashion. I would like to do this, so here's the setup:
A vault in a bank has not been opened in a Very Long Time. There's an anti-magic field on the vault to prevent magical-based thefts. When it was last closed, there was no body in it, but when it was opened again, there's a corpse in there.
The question is, how did it go down?
As a side note, anyone have any general mystery suggestions/plots they've done?