The deeper I look the more puzzled I am.
I start with the idea that partner has to have had J109x in spades and has thrown away his stopper, generating an important trick for declarer. That is usually a sign that it is imperative that we cash out.
Any cash out means he has AKxxx in diamonds, and I can't find many constructions on which declarer has a 2N rebid. Surely he is likely to be 3=4=3=3?
If he is, then partner can't be cashing out in diamonds.
Can he have J109x x Axxx AJ10x? And declarer AKx Axxx KJ10 Kxx?
No, because he shouldn't encourage in diamonds and he should have pitched a preserved diamond 2 on the second heart rather than establish the 8th trick for declarer.
How about J109x x Axxxx Axx? No, because he'd never pitch the spade, and he still shouldn't, imo, signal this way with, say, J109x x Axxxx KJx. Otoh, that makes for a more plausible 2N rebid, with KJ in diamonds rather that the dubious 3=4=2=4 with that well-known stopper, Jx in diamonds.
I suspect I'll have an 'oh yes' moment when the answer is revealed but for now I am going to trust partner and cash the heart and lead the diamond.
Forget all of the above....for some reason I assumed dummy held our club Q! Oh well
This post has been edited by mikeh: 2012-November-18, 00:30
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari