East had no better call than one no-trump to begin with, but he might have redoubled at his second turn to try to get clubs into the picture. It was not critical here, since the vulnerability persuaded South to take a shot at four spades once East ran.
On the diamond lead, declarer sensibly preserved dummy’s K-J tenace. He won in hand and then led a low heart, angling to ruff out the suit while plenty of entries to dummy remained. East won, cashed the trump ace and got out with another trump. This was unlikely to cost a trick, and it prematurely extracted a key entry from the dummy. Declarer continued his plan with the heart ace and a heart ruff before drawing the last trump.
South was now an entry short to establish and enjoy the long heart, but he had another trick up his sleeve. With the heart jack known to be on his left, declarer deduced that East must hold all of the outstanding minor-suit honors. If so, East would come under pressure on the run of trumps.
In the four-card ending, declarer had reduced to the diamond eight and A-x-x in clubs facing the diamond K-J and J-x in clubs. East had to keep the diamond queen guarded, but baring a club honor would establish dummy’s jack. There was no possibility of deception after the auction, and West’s spot-card opening lead had revealed East’s diamond length. East therefore reduced to doubletons in each minor, whereupon declarer threw him in with the club ace and another club to lead around to dummy’s diamond tenace.