To whom it may concern,
I, Ms. Hortense Q. Geizkragen—cantankerous octogenarian billionaire, riddle connoisseur extraordinaire, and puzzling free agent—have decided to end my time on this Earth.
No, I'm not dying—quite the contrary! I'm hopping on my private rocketship to fly to my private space station, where I will spend the next five to seven decades in perfect solitude and hyperbaric-controlled comfort.
Before I go, there is the matter of my stunning collection of rare puzzling artifacts, stretching back to the dawn of recorded time.
I have amassed this unparalleled collection piece by piece over many long years, at great pains to myself. If revealed to the general public, it would shake the very foundations of society as we know it. I shall only bequeath the collection to the World's Greatest Puzzler (after me, of course). I would sooner lock it away forever than have it fall into lesser hands.
And lock it away I have: in an impenetrable bunker, in my underground lair. There is but one key to this bunker, which I have buried somewhere in the United States of America.
I have crafted 10 astonishingly brilliant puzzles, at 10 well-known locations throughout the U.S. The key is buried at one of these locations. Solve all 10 puzzles, find the key, and the collection is yours.
That is, if you get there first. I sent the same offer to your rivals at the Quizzical League; they're already hard at work. I would not underestimate them.
So. This is your chance. Are you the worthy steward of the greatest mysteries known to humankind?
Your destiny awaits.