North’s jump to four spades showed a terrible hand with a spade fit and 0-3 high-card points. South didn’t need much to have an adequate play for slam, so he carried on anyway.
South won the opening heart lead with his ace and took a moment to plan the play. Dummy didn’t have much, as advertised, but the doubleton diamond and the nine-eight of trumps provided hope. One line of play was to cash the ace of clubs and then lead the queen of clubs. Should the opponents hold up the king, South would revert to diamonds and play to ruff two diamonds with dummy’s high trumps. If an opponent took his king, there were enough clubs in dummy to discard three of declarer’s diamonds. This would need a trump split of no worse than 3-1. It was possible that the opponent who won the king of clubs could play another club for his partner to ruff. South could ruff high, of course, but there would no longer be enough clubs in dummy to discard three diamonds. The diamond finesse would then be needed.
South found an elegant improvement on this line. At trick two, South led the queen of clubs! West could win with his king but could do no damage to the contract. Should West duck his king, South would play to ruff two diamonds. This line needed clubs no worse than 4-2 and spades no worse than 3-1. No finesse would ever be needed. Well done!