1.Rc1! (2.Rc4+ Kd5 3.Sc8  ~ 4.Qe4# & 2...Kd5 3.Re4+ c4/Kd6 4.Qe5/Qe7,Sc8#),

1...Sc6 2.Qd7+ Ke5 3.Rxc5+ Ke4/Kxf6 4.Qd5/Qxf7#,

1...gxf6 2.Qd8+ Sd7 3.Qxd7+ K~ 4.Qd5#,

1...Se3 2.fxe3+ fxe3+ 3.Bxe3+ Bxe3+ 4.Qxe3#,

1...c4 2.Rxc4+ Kd5 3.Sc8  ~ 4.Qe4#,

1...Rxa7 2.Rc4+ Kd5 3.Re4+ c4/Kd6 4.Qe5/Qe7#.

Separation of  threat's dualized continuations in variations 1...c4 & 1...Rxa7.