Kidnap

Mr Smith was seated comfortably in his living room one evening when a rock crashed through the window and landed at his feet, amidst a shower of splintered glass. To the rock was attached a note: "Unless you pay us £10,000 according to instructions, we will kidnap your wife."

After some thought, Mr Smith sat down at his desk and penned a reply:

Gentlemen,

Your rock of the above date has been received. I don't have £10,000 at this time. However, please keep in touch, as your proposition interests me.

J. Smith