Matchpoints.
East led his two top hearts and shifted to the club 3, won with the 9 (an error, but I overcame it). It certainly seemed unlikely that East had the ♦K, and it also seemed likely that West had some diamond length. It took me a few moments, but I worked out that I could bring in the diamond suit for one loser if East had Tx or Jx (or JT doubleton, but that is less likely than Jx or Tx together).
So, I crossed to the ♠A and led the ♦9 and ran it to the J - an Intra Finesse! I won the club return in dummy (fortunately it was not ruffed) and led the ♦Q - K - A - T. Success!!
There are other layouts to bring in the diamond suit for only one loser (for example, a singleton diamond J or 10 in the East hand), but this one was fun.