Solution
1. Qc2+ Qxc2 2. c8(Q)+, followed by Qxc2
White uses the move Qc2+, to attract the black queen to the c2-square–where she will be exposed to the skewer tactic, c8(Q)+
Of course white could not play 1. c8(Q), since the c7-pawn was pinned by the black queen.