Solution:
1...d5+[a] 2.Rc7#
1.Nc8? zz
1...d5+[a] 2.Nd6#[B]
1...Kd5[b] 2.Nb6#[A]
but 1...b3!
2 tries skipped1.Rxf4+??
1...Kd5[b] 2.Qd4#[C]
but 1...gxf4!
1.Qd3+??
1...Kc5 2.Rc7#/Bb6#
but 1...Kxd3!
1.Nc6! zz
1...d5+[a] 2.Ne5#[D]
1...Kd5[b]/b3 2.Qd4#[C]
1.Bb6! zz
1...d5+[a] 2.Rc7#
1...Kd5[b] 2.Qe6#/Qd4#[C]
1...b3 2.Qd4#[C]