Put yourself in the West seat for this defensive problem.
North’s two no-trump confirms a fit in hearts and sets up a game force, so South’s jump to game denotes a minimum opener, almost denying a singleton or void on the side unless the singleton is a high honor. (As an aside, there is much to be said for opener using a three-club response as any minimum, giving away much less information. Responder can then jump to game and give nothing away, or ask for more information if still interested in slam.)
You are naturally loath to underlead kings against suit contracts, so you put the ball into play with a passive club, deciding to select a slightly offbeat top card from three small. Declarer calls for the ace as partner follows with the two, discouraging. Then comes the heart queen to the 10 and your king. Plan the defense.
Since your partnership uses suit-preference signals in trump, partner’s 10, if from a doubleton, must be a high card asking for a shift to the higher side suit, spades. In that case, partner has the spade ace, and you might be able to secure three tricks in the suit right away.
If you were to shift to the spade nine, declarer could play low, forcing the ace from partner to keep dummy’s queen as a stopper. It must be better to shift to the spade jack, a surrounding play to pin a hypothetical spade 10 in South’s hand.
Here, your spade jack holds, and you continue with the spade king and another spade to set the contract. Failure to cash out would see declarer throw a spade on the fourth club and make his contract.