By Eddie Kantar 
Courtesy of KantarBridge.com
You and your partner were not using Key Card Blackwood, so after partner supported spades and you found out via regular Blackwood that partner had one ace you had no way of knowing whether he had the ♠K as well. You fearlessly bid 6♠ anyway.
The opening lead is the ♥J. Plan the play.
Solution
You are off the ♣A and need to find the SK with East, so assume it is there. First hurdle. Next, you must allow for East having all four spades in which case you need to lead spades twice from dummy to pull in the suit.
Make the key play of the ♥K at Trick 1 and the next key play of the ♠10 at Trick 2. If East plays low, run the ten, and repeat the finesse. If West has shown out on the first spade, you can return to dummy with the ♦A to finesse spades one last time.
There are two traps here: (1) winning the opening lead in your own hand. Now you may need two dummy entries to play spades and if East has a singleton heart, you don’t have them. (2) even if you win the ♥K at Trick 1, you must start with the ♠10 at Trick 2. If you lead low to the queen and West shows out, you will need two more dummy entries to pick up the spades and you only have one.
The full deal: