West had overcalled my 2NT opening with 3♣ and we somehow scrambled to 6NT, don't ask how! But in fact 6NT is the best contract on this deal, provided one can place the diamonds correctly!
Alas! After winning the K♣ lead with the A, I laid down the A♦ and was taken straight to the slaughterhouse. A moment's thought could have told me, W for his overcall must have at least six clubs, so he's less likely to hold three diamonds - and I have an entry to dummy. I should have led ♦ to the K and taken the marked finesse against E if necessary...
Ah well - we learn from our mistakes. Would you have got it right?