Alright, time for puzzle #2!

Today's puzzle is not quite a difficult as yesterdays, but I still really enjoy it.  To go along with the new puzzle, I've changed the names of the post so that they're a bit more intuitive (I didn't want people to think I was starting a play-by-post Dungeons and Dragons game after all )

Same rules as yesterdays:

1.) White must mate in 3 moves.  No exceptions.  Assume that you have 1m30s on the clock and each move takes you 30s to make (whether it actually takes you 30 seconds, 5 minutes, 10 minutes or 10 seconds, just assume it takes 30s).  If you don't mate in 3, it's game over and black wins.

2.) There is only one key move to obtain mate in 3.  (If you find others, please let me know )

3.) No first key move will result in a check, a capture, or involve the promotion of a pawn.

You can find previous Dungeon Puzzles below:

Puzzle #1 

My apologies Vin, I had put a bishop instead of a pawn.  I'll correct the puzzle now.  Thanks for catching that

*Update* I jotted out the FEN for this puzzle years ago and at the time (though the diagram was correct) accidently put a B instead of a P, ahh well.  It's corrected now. 

Why black didn't move 2....Kxd6? This would have delayed the mate by quite a few moves. Am I missing something?