As East, you hold:
Q7
943
AJ8
K9862.
LHO opens 2 and RHO responds 2NT, interested in game (asking for a Feature). And you?
Pass
3
Other
Opener bids 3NT (their agreement--which is not "standard"--is that this shows 6 hearts and a flat minimum) and RHO bids 4.
Partner leads the 6 as shown and dummy plays low. You play...
8
J
A
Your J holds the trick as shown. What do you play to trick 2?
Q
7
A
8
This is the position after partner wins the K. Partner plays a club. Why?
No clue.
Because West knows that no more diamonds will cash. He knows you have the A, but declarer has none left. There is no future in diamonds. Dummy's spades look threatening. The best chance for defensive tricks is clubs.