The Lady or the Tiger?

You pick up ♠ xx xx Axxxx ♣ Jxxx. LHO opens a spade and your opponents sail smoothly into 6♠ (1S 3S 4NT 5D 6S). Partner leads a low spade and dummy comes down with....

♠ JTx
KJxx
xx
♣ AQTx


Declarer proceeds to take 3 rounds of spades, partner following to all 3, winding up in hand.

She takes a round of clubs with the king, leads a low club to the ace, then plays the queen, pitching a low diamond. She appears disappointed when the J♣ doesn't appear.

Declarer now sets to work on the hearts, leading a low heart from the board to her ace, returns another, successfully finessing the jack. She calls for the king and sighs when you play a low diamond. (Your partner followed to all 3 rounds of hearts.)

Declarer goes into the tank.....then leads a low diamond. What do you play, and why?

SOLUTION