Analysis:
If West has the ♣K, then a club switch will be good for them. The important thing here is not to give that away to East. Play the king on the first trick, not the queen. Maintain an even play tempo: watch East’s card. Don’t start playing from your hand as though you don’t care what East plays.
We play a spade to the ten and East wins with the jack but leads a diamond instead of a club. We play the ace, not the queen. Again, maintaining an even tempo so that East thinks his partner has the queen. Now when we try another spade finesse and East wins again with the king, he makes the same mistake and leads a third round of diamonds.
When the spades fall 3-3 we make the contract. Afterwards East discovers that a club lead would have beaten the contract because West held strong clubs over our queen, and that they let us take nine tricks despite the three important defensive cards all being in the wrong place.
It would be similarly deceptive to play the ♦Q on the first round and the ace on the second round. The important thing is not to play the king or queen on the second round when East leads through, because that would give away the location of the third top honour.