Christian Poisson (France)
 
#16 3+2

1…Ka7 2.Kc7 Ka8 3.Kb6 Kb8 4.Nb7 Kc8 5.Kc6 Kb8 6.Nd6 Ka8 7.K×b5 Ka7 8.Ka5 Ka8 9.Ka6 Kb8 10.Kb6 Ka8 11.c4 Kb8 12.c5 Ka8 13.c6 Kb8 14.c7+ Ka8 15.c8=Q#
4…Ka8 5.Nd6 Kb8 6.Kc6…
1…b4 2.c×b4 Ka7 3.Kc7 Ka8 4.b5 Ka7 5.b6+ Ka8 6.b7+ Ka7 7.b8=Q#
1.Kc7?
but 1…Ka7!
1.Kd7!
Kb8 2.Kc6 Ka7 3.Kc7 Ka8 4.Kb6 Kb8 5.Nb7 Kc8 6.Kc6 Kb8 7.Nd6 Ka8 8.K×b5 Ka7 9.Ka5 Ka8 10.Ka6 Kb8 11.Kb6 Ka8 12.c4 Kb8 13.c5 Ka8 14.c6 Kb8 15.c7+ Ka8 16.c8=Q#
5…Ka8 6.Nd6 Kb8 7.Kc6…

Fata morgana, duel black King/White King, Flight-giving key    (Author)