Answer Notation:
1) Qxd7*N+; Ka7
2) KBd4+; Ka6
3) QNa4#
Answer Explained:
White Queen captures d7, plunders Knight vest, check. Black King escapes check by moving to a7 (only option). White KingBishop moves to d4, check (by power of Bishop vest). Black King again escapes check by moving to a6 (only option). White QueenKnight moves to a4, checkmate.