When North cue bid four clubs, despite holding minimum values, he was following the general principle that “cue bids below game do not promise extras.” The slam was no more than the jack of clubs away from being cold. As it was, it seemed to rely on a successful club finesse—a finesse that rated to lose from the auction. South showed that it was better than that.
South carefully played low from dummy at trick one, ruffing it in his hand. South thought it quite likely, from the auction and the lead, that East held both high hearts. He drew trumps in two rounds, then led a diamond to the king and a diamond back to his ace, before ruffing his last diamond in dummy.
Declarer next led the queen of hearts from dummy, which was covered by East with the king. Rather than ruffing this trick, South elegantly discarded a low club. East was on lead with a surprise heart winner, but he didn’t like it one bit. East had a choice between leading a club into the ace-queen, setting up the heart jack, or yielding a ruff-sluff. Whatever he chose, South had his slam and a hand to brag about for at least a month.
Note that the slam would have failed had South played a heart honor from dummy at trick one. It’s also worth noting that, on this line of play, the location of the king of clubs was not relevant.
