Deductive Puzzle #6

Good job everyone! I'm gonna keep them to one puzzle a day, so you're gonna have to wait until tomorrow for the next one, but in the mean time, here is a rather strange one I once stumbled across to hold you guys over! 

It's called Mate in Zero, and you need to figure out just that. How can you Checkmate the black king without touching any of the White pieces?

Oh, I'm sorry I missed this one -- nice work guys.

For the Mate in Zero puzzle -- is the answer by any chance to simply flip the board so that a1 becomes h8 and visa-versa?

I considered that, but then how did both pawns come to place the Black King in check?

I think, instead, that we need to complete an En Passant capture, but I can't see, yet, how to distinguish between fxe6 e.p. or bxc6 e.p..

EDIT: The e5 pawn had to have come from the d-file because of all of the Black pawns on the kingside.  Thus, the move was bxc6 e.p., and all that remains is to take the Black pawn from c5 off of the board.

Ahh, that makes sense.  I knew my solution was too obvious and simple.

I didn't get to contribute to #6, so I'll give you an answer for this one.  Black's last move was pc5; white has responded with an enpassant capture, b5-c6. You "complete" the move by removing the black pawn, mating the black king. In doing so, you have not "touched" a white piece.

Edit: I think the same thing works on the other side as well . . .

Edit #2 - Nope, Grobe is correct - it only works with the c-pawn, not the e-pawn.

It must be Black's c-pawn because the e-pawn can't have started on that file -- there are already four pawns to the king-side of it and none of them could have come from the queen-side based on how far they've advanced so it had to capture its way to the e-file.  This means it can't have just moved e7-e5 on the prior move so Black's last move must have been c7-c5 while the White pawn was on b4.

I'm really enjoying these retrograde puzzles, although that last one should more accurately be called Mate in ½.

I guess that would give it away....