Declarer played low from dummy on West’s opening lead, so West continued with the *♣J, which also won the trick. The club continuation went to dummy’s king and East’s ace. Declarer ruffed the latter and paused to consider his options: he had a probable loser in trumps as well as an almost certain loser in diamonds. The best chance might be to make the former disappear in a “Devil’s Coup.” For that to occur, trumps would need to be 2-3 with split honors. Declarer would also need to be able to cash the red-suit winners, with East having more hearts than West.
Accordingly, declarer continued by cashing the ♥A and ♥K, then ruffing a heart low in dummy. Next, he cashed the ♦K and ♦A and led his remaining heart. West discarded a club and dummy’s ♠7 won the trick. Declarer next move was to lead a low diamond from dummy. East discarded his remaining club and West won the trick with the 9. West was now endplayed, reduced to the doubleton jack of trumps and the ♦Q. If he exited with a trump, declarer would make the rest of the tricks by playing for the queen and jack of trumps to be in different hands. West played the ♦Q and East could do no better than ruff with the ♠Q. Declarer overruffed with the ace and led a low trump from hand, putting in dummy’s ♠10 when West followed with the 6. The ♠K was declarer’s 10th trick.
Note that if East had started with a queen-low or jack-low in trumps on the above red-suit layout, then he could have defeated the contract by ruffing the third round of diamonds low and then exiting with his remaining trump. The full deal: