Molson Hart

White Queen F4

It's all about the Black Queen position. You must mitigate that position while still putting the black king into check so that he must play defense. You can then position your rook and bishop as necessary for mate.

Bishop and rook order of moves dependent upon the choice of white king option on next move.

My first instinct was white queen to C5 but that would not mitigate the threat of the Black Queen. Took a couple quick mind iterations to see that the threat of the Black Queen would cancel that quickly. Thus, move White Queen to play offense and defense at the same time.

Spoiler alert: * * * * * * * * * * * * * * * * * * * * Second moves: If BKb3, WBd1 If BKc1, WRd1