RE: Extra tough Christmas chess riddle (#69). / Knacknuss-Weihnachtsschachrätsel (#69).

3.. Ng4+ Bf4
4.. Nxe5+ Kf6
5.. d4 (Threatening checkmate on f8) Kf5
6.. g4+ Ke4
7.. Re1+ Kxd4
8.. Nf3+ Kd3
9.. Rc3#