Give me the position of Emperor of the Planet.
Technically, I didn't say a name, nor a location.
If that won't 'fly' with the Wizard then
"Give a Wizard the body of an adonis."
Either he gets it (as he is the only wizard), thus leading credence to the theory that there is only a single wizard, or he doesn't in which case there are far more. I can then don my detective coat and go looking for them, in search of a mystery.