North must have been madly in love with his queen of hearts and was trying to impress her with his aggressive bidding. They’ll be planning the wedding if South can make this one.
East overtook the opening diamond lead with the queen and shifted to a spade when South allowed the queen to hold. South rose with his ace of spades and continued the suit to West’s king. West now made the excellent play of a third round of spades. Should partner be able to ruff with the nine of trumps, West would have a second trump trick to defeat the contract. No luck there, as East ruffed with his five and South overruffed.
Declarer led a low heart to dummy’s queen as West ducked his ace. The 10 of clubs was led for a successful club finesse, followed by a club to the jack. The heavy lifting was already done, so South got around to drawing the outstanding trumps. He led the king of hearts from his hand. West won with the ace but there was nothing for him to do. When South regained the lead, he drew the last trump and claimed 10 tricks, assuring his invitation to the wedding!
Note the importance of ducking the diamond lead at trick one. Had South won with his ace, the 10 of hearts would have come into play later as the setting trick.