1.e7Na3+
2.Kb6Nc4+
If 2... Qa4 3.Nd5 and the e-pawn queens
3.Kc5Qa4
4.Rxb4!
The rook lies in ambush and sets up the final combination...
4...Qa7+
5.Kxc4Qxe7
So, the queening pawn is captured and all is well - or is it?!
6.Ng6+!fxg6
7.Bf6+!Qxf6
8.Kd5+
The rook springs from ambush!
8...Kg5
9.h4+Kf5
10.g4+hxg4
11.Rf4+!Bxf4
12.e4#
A nice composition - not one unnecessary piece on the board!
Kazantsev (1967)