I should warn everyone not to lose sleep over this one. It is tough to find the solution on you own unless you are looking in the right place. It is a classic puzzle so some may have already seen this one.
White to move, Mate in 3
Now there is a quark to this one, but it is completely within the normal rules of chess. Black has a defense. If you are thinking you have a mate in two by
1. Qf1+ Kxh2
Black's defense trumps that. The key is to find black's defense and how to defeat it.
Because this one can be hard, I will try to give as many hints as possible. Spoilers will be posted in a day or so.