West leads the king of hearts, follows with the ace (east showing out) and west leads a small heart, east ruffing. East returns the jack of spades. Are you in an impossible contract?
Not hopeless but not very good, either. You can set up a heart in dummy but that only takes care of one of your four clubs. Somehow you have to play clubs for no losers.
If either opponent has a singleton king of clubs you can succeed. But that is unlikely. But it could happen.
Question: How can you find out if someone has a singleton club?
Count. East returned the jack of spades and if you draw the last trump, you see West had it. You know that East has two spades and one heart and probably six diamonds. This means East has four clubs and West has two. No singleton king of clubs on this hand.
Question: Do you have any chance at all?

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-- -- 2♦ Dbl
3♦ 4♦ Pa 4♠
Pa Pa Pa