This deal is a defensive problem from the teams at Bolton Bridge Club's excellent congress held annually in early September.
Partner leads the nine of diamonds which declarer wins in hand with the queen.  Declarer plays a small trump, the eight from partner and dummy wins with the queen.  Declarer now leads a club from table which you win with the queen while declarer plays the nine and West the two.  What do you play?

Solution
 
It looks as though the initial lead was a singleton and that partner's trumps are ace, ten, eight since declarer would have raised to four spades with the trump ace and the queen and jack of diamonds.  The obvious defence is to give partner a diamond ruff, but what happens after that?  Declarer will be able to draw trumps and run the diamonds, since unless partner's hearts are AQJx he cannot switch to a heart profitably after taking the diamond ruff.  The heart lead must come from East and now is the time to do it.  The winning defence is to play the ten of hearts.  Declarer will win in the dummy, but is stuck there and cannot avoid losing two hearts, a club and two trump tricks.
 
The full deal

Dealer  N			KQ6
NS Vul			K54
			AK10642
			4
	A108				J9
	AQ86				1097
	9				873
	108632				AKQ75
			75432
			J32
			QJ5
			J9