This looks like a difficult problem. It seems to me that it comes down to finding the answer to the question: Is declarer trying to make an otherwise unmakeable contract by playing for the
♣King to be onside or is he being careless and risking an otherwise makeable contract? If declarer is missing both the major suit aces, then he is more likely play the
♣Ace and play to discard diamond loser(s) on the clubs after drawing trumps. So from declarers play it looks more likely that he has the
♠A then the K
♥. What do I make of partner's
♣8 return. Well if he has the 10 also as is likely, then the 8 and 10 are equal. Normally in this kind suit preference situation I would not expect the trump suit to feature in the considerations, but here with a choice of probably 4 cards I would expect partner to play a low card at least to tell you not to play a heart and the
♣10 if he had
♠Ace.
So return your smallest heart.
That might still not be good enough because declarer having J9 can ruff with any spade. Now declarer can enter dummy with a diamond to pick up partner's possible
♠K. Now it depends on declarer's spades. It looks like with only 4 there could still be a diamond loser.
So be brave and trust partner and not declarer.
But I am not confident that there is something I am missing.
Bidding:
- - P 2♥
X 3♥ 3♠ P
4♠ P P P
Lead the 7♣, dummy ducks to partners king. East follows with the 9.
Partner returns the 8♣.