i have a couple of questions, i assume the lead is from doubleton? (not sure of the marking). if so, why didn´t N continue with spades killing your high spade(s) (he knows you hold QJ of spades from your nt bid)? if you only have one spade discard for the diamonds then you have to play for the club finesse (more likely than the diamond finesse) and from his point of view you make. also, if S holds K of clubs, why didn he just return club at trick two? what can he gain by playing A of spades? i mean, if S led from singleton he has to play low spade at trick two in order to bring declarer down, playing the ace has no benefits. if you do take the club finesse and it holds, 3-1 trumps doesn´t bother you, 4-0 does. you have one ♦ discard on the A♣ and then you can play Q♠, if south ruffs, overruff and enter the hand with trump. if north has a trump you´re fine, if he shows out, there is still a chance for a diamond expas. if you decide to not take the club finesse you should at least try to ruff out some clubs, maybe the king drops (although unlikely) anyway, the first thing is what would sway me towards taking the club finesse.