Let me add some questions (since everyone does on mine!!)
What carding is NS doing? We can expect north to have 4
♦ on this line of play, so
♦2 is either "attitude" (I don't like diamonds but when dummy played low and East won the ACE we would have been able to figure that out. If count, must be udca. If suit preference, then what was diamond Five then Diamond three later? Anyway, what signals could partner have been trying to send us in his play in diamonds (and possibly in clubs if, as we need if we are beating this, he has two or three clubs).
Here is a logical possibilities:
1) diamond 2 "attitude" (I don;t like diamonds). There is no need to tell us that when dummy plays the 9 under our 10, so....
2) diamond 2 "count" (UDCA in this case), diamond 5 "suit preference for spades"
3) Diamond 2 "suit preference for hearts", diamond 5 "original count" (if normal) or "remaining count (if UDCA)
4) Club 3, off suit trump signal (suit preference for hearts, assuming partner has 2 or more clubs)
But let's analyze the hand without worrying about partners carding, because we were not told what it means.
Partner has opened light, with no hcp in either minor. Partner did not reopen with a double, despite being light with only four diamonds, so he is probably 4=3=4=2 or 3=4=4=2. If he was 4=4=4=1 he should have reopened with a takeout double in case we had a trap pass hand. Partner could also have 3
♣'s but if so, at best Declarer has something like
♠xx
♥Kxx
♦Axx
♣KQ9xx where he will eventually come to 4
♣, 2
♦ and a
♥ for down one. With six clubs, he is probably 2=2=3=6 or 1=3=3=6 (he will not be 3=1=3=6 as that gives partner five hearts and only 4
♦).
If he had the
♥Kx(x) declarer might have tried leading towards it instead of messing around with diamonds,so you can place partner with something like: spade ACE, heart AK (or AKQ or AKJ) for his hcp, although AQJ in hearts is still possible. With 3=4 or 4=3 in the majors.
I will cater to partner having
♥AQx(x). I will ruff the
♦, cash the
♣A, and since I don't know where the
♠Ten is, make the surround play of leading the spade JACK. If declarer is 2=2=3=6, three rounds of spades will force him to lead a heart even if he has the king. If he is 3=1=3=6, and covers the jack of spades, partner will return a spade and we grab 3
♠ and the
♥A plus two clubs. IF he ducks the jack of spades, we continue spades, partner wins (per force with Ax originally), and lays down his heart ACE, dropping a potential singleton heart King and we get a spade at the end.
As for declarer's play. With six clubs, declarer should have won the first diamond on dummy and leading the club jack (five clubs, three diamonds just making). Yeah, yeah, I know, we are taught to avoid blocking the suit by winning in the short hand. But here the suit you must not block is clubs, not diamonds! Would probably have been a better "play" problem for beginners and a better defensive problem for intermediates.