The NS pair were playing a 14-16 1NT and over North’s enquiry, opener showed four spades and responder simply bid 3NT. The rule for flat hands opposite a 1NT opener is that with a minimum of 24 hcp between the hands, always bid game. With a maximum of 25 hcp always stop in 1NT. This rule works well and avoids the need for invitational bids and all the associated hesitations and angst! Since the spades had been bid, West led the fourth best 8D and declarer has to make a plan. There are three club, three heart, one diamond (because the lead is giving you one) and one spade trick giving a total of eight tricks. Declarer needs to see where a ninth trick might come from. The diamonds might be 3-3 or the ten might be onside and the hearts might be 3-3 or the jack might come down doubleton or the heart finesse might work. So, keeping these in mind, declarer plays small from dummy and East plays the king and returns the six.
Declarer tried the nine in case the lead was from A87 but West plays the ten and the queen wins and the position is clear. Next declarer plays a club to the king and a spade towards the queen which holds. It’s clear at this point that West holds the AS as well as the AD and so declarer must remove all West’s cards in hearts and clubs before throwing him in with a diamond. Declarer plays the ace and queen of clubs and the ace, king and queen of hearts testing the heart position. Now when he exits with a diamond, West wins two diamonds but must concede a trick to the king of spades. The initial play of the spade towards the queen is an example of Morton’s fork. If West rises, declarer gets two spade tricks for his contract. If West ducks, he gets endplayed as here.
Perhaps, with such good spade intermediates, West should have led a spade to North’s queen. Then, when declarer has to play diamonds himself, he must lose three tricks plus two spades when East leads one through.