Anyone? =P
From a game...
First of all...is this game ongoing? second of all... I would move Bc5+ (Highlight the space there).
No, this isn't an ongoing game. This is from a 3 minute game that I watched.
I'll give a hint (highlight): Black is played by a chess engine.
I agree with dc1985 - Bc5+ looks like a reasonable move, but I couldn't find any continuation that did anything for black after that. If there's a winning line for black, it's way above my level . . .
I think I have it. Bc5+ Kh1 Rxh2+! Kxh2 Qxb2+ Kh1 Bf5! where the threat on the Queen and Rh8# appears to be decisive. If that's it, cool puzzle!
Well, the move has to deal with white's immediate threat of Qg6# for a start.
That restricts candidates to either a checking move,a move defending g6 or a move blocking the white queen's line to g6.
Bc5+ looks best to me - and seems to lead to material gain for black.
EDIT: And SirDavid beat me to it. Of course 23. Rf2 could be a better defence
What would you play if you were black?