You are South in four hearts after the bidding shown below:
West leads the ace of clubs, East playing the deuce. At trick two West shifts to the jack of spades. You play the queen, East plays the king, and you win with the ace.
You have one spade loser and two club losers. How are you going to handle the trump suit for no losers? The percentage play when missing three trumps is to finesse for the king. But how are you going to get to dummy to do that?
Instead of the heart finesse, maybe you can discard your losing spade on the ace of diamonds? But that requires that you drop the singleton king of hearts, otherwise the defense will cash their spade winner before you can get to dummy.
Is that king of diamonds a mirage? Maybe it would be helpful for you to think of it as a low diamond. Does that make you decision any easier?