(31.05.2014) Welcome twomover from the Russian expert showing the fashionable "Le Grand" theme (Reversal of threat-mate).

              Try:  1.Sf4? (2.Qb3# A)

                       1…Kb5! 2.Qa4# B

                       1…a4 2.Qb4#

                       1…Bd5!

              Key: 1.Se4!  (2.Qa4# B)

                        1…Kb5! 2.Qb3# A

                        1…Be7/Rxe4 2.Sb6/Be2 # 

             King’s Le Grand with preliminary masked interference (Author)

These queen mates have been shown previously in a miniature. 

http://www.yacpdb.org/?id=143144  This is however a more complex scheme.(Seetharaman)