Chess Puzzle - 2

Black to Play and Win

This is regarded as one of the well known traps laid by Black in  Ruy Lopez.  
The move order goes on like this 1) e4 e5 
                                                        2) Nf3 Nc6
                                                        3) Bb5 a6
                                                        4) Ba4 d6 
                                                        5) 0-0 Bg4 
                                                        6) h3 h5!?


Black has given up on his bishop to hand over a material advantage to white but has a mating attack on White following white's capture over the bishop.


So what happens after 7) hxg4?

Answer:


After 7) hxg4 follows 7)... hxg4
                                     8) Ne1 or Nh2(forced. Any other move would result in the loss of knight)
                                     8)..... Qh5 and mate follows at h2 or h1..........