Obviously the Club finesse must be right, still only giving you 11 tricks. East probably has seven hearts for his bid and the spade play means he has at least two spades (West would not lead low from AQxxx). To have any chance of success, East must also have two clubs minimum and therefore no more than two diamonds. That rules out trying to ruff a diamond in dummy. There are not enough entries into dummy to establish a spade without first clearing trumps because of the chance of a heart ruff.

Finesse the club and draw five rounds of trumps,throwing 2 spades and a small heart from dummy. Assuming a 4-2 spade break, Now play your Heart King and aheart to the Ace in dummy. West cannot afford to bare his Spade Ace (or you will ruff a spade and make 7!) so he must come down to 3 diamonds. Play King and back to your Ace of diamonds, concede a diamond, ruff the return and the thirteenth diamond is your last trick.