I tried the trapped mate idea (3. n to h6) and the puzzle told me that was a wrong move, coming up with the revealed check 3. n to d8 instead. Yet when I entered n to h6 into the alternative solution feature it told me that the move was already present in the solution . . . so why didn't it let me do that move the first time I tried it?
@travis55: the problem is that the delaying tactic of 1...qe6 prolongs the agony by one move, and the smothered mate solution, whilst elegant, takes 6 moves, not 5.