1.Sc2? - 2.Q*b7(A) + K*d6 3.e8S(B)#

but

1...B*d4(a)!

1.e8S(B)! - 2.Sf6(C) + K*d4 3.Sf5(D)#(MM)

1...B*d4(a) 2.Q*b7(A) + Kc5 3.Sd3#(MM)

(2...Ke5 3.Sd3#)

1...K*d4 2.Sf5(D) + Ke4 3.Sf6(C)#(MM)

( 2...Kd5 3.Sf6#)

Model mates with 3 white knights, each one of them performing mating move in one of the MM variations. Dombrovskis.