Dacha Tactics #25 - dark nugget incoming!

From a blitz game of mine in a wild time scramble! Material is about equal -- let's look for color $. So we have a light bishop vs a rook. This means we are ahead on light, but behind on dark. White's king is precarious but alas , stands on a dark square. How to replenish our dark and finish him off?

Interact with the puzzle below. If you get stuck, you can always click the "lightbulb" icon in the lower-left of the puzzle frame. Good luck!