Once again, we are cribbing from Yakov Neistadt's Improve Your Chess Tactics (New in Chess, 2011). And once again, our theme is deflection. An enemy piece is performing an important function: can you make it move so that it's no longer performing that function?
Two hints: I wrote "wow" in the margin of the book, and even Houdini took a second or so to find the winning line. But what would an American do at the Opéra de Paris?
Mackenzie-NN, Manchester 1889
White to play and win