After East passes, you open 1♠, partner bids 2NT (Jacoby), you show your singleton diamond, partner checks for aces, and hoping you have the ♥Q or the ♣K, catapults you into 7♠! (Well, you have one of those cards.)
West leads the ♥J. East plays the ♥4. Plan the play.
Okay, a little explanation: You had a 60 partial before this deal, so North’s 3♦ is a slam try.
West leads the ♣J. Plan the play.