
Solution

1… Qxa3+ 2. Kd1 Qa1+ 3.Ke2 Qxh1
Black employs a skewer (2… Qa1+) to win the hanging piece (undefended rook) on h1.
Note that 1… Qxa3 2. Kb1? Qb2# is checkmate.
1… Qxa3+ 2. Kd1 Qa1+ 3.Ke2 Qxh1
Black employs a skewer (2… Qa1+) to win the hanging piece (undefended rook) on h1.
Note that 1… Qxa3 2. Kb1? Qb2# is checkmate.