Someone you're vaguely associated with and are known to dislike turns up dead.
You were in watching tely, not paying attention though, it's a bit weak, won't stand up to interrogation. You panic and make something up, something absurd, perhaps involving the death of a golfish.
So, where WERE you on the night of the murder?
(you can't cop out by getting a mate to lie, that's against the rules of this game)