Black has a forced win with Rg6 +, and white is mated in at most 3 moves
white can delay the mate by blocking with Bishop and Queen
with White to move two possible moves are Qh5 and after Rg6+ then Qxg6
more likely is f3 Qxe3+ , Qxe3 Rxe3
When you see the major pieces line up then start thinking about pins and skewers
this lining up can be either how a Rook moves, or how a Bishop moves
possibilities are : b3, g4 being the forking moves
if g4 then black can save the piece by Re5+ - King moves and then the Knight runs away too
note that if the Knight on h5 is a Bishop then that doesn't work and has to be threatened or prepared with f3 or h3
White also has the chance of skewering the Rook with Bc8+