Both sides vulnerable.  
South deals.
                              North
                              S: A Q 3 2          
                              H: A           
                              D: Q 10 8      
                              C: A K J 8 3
            West                             East
            S: 8 7 4                         S: 10 9 5       
            H: K Q 10 7 4 3                  H: J 8 2      
            D: J 7 6                         D: 5 4 3             
            C: 10                            C: Q 7 5 3     
                              South                         
                              S: K J 6
                              H: 9 6 5      
                              D: A K 9 2   
                              C: 9 4 2    
          The Bidding:  
                  South    West    North    East                  
                   Pass     2H      Dbl     Pass
                    3S     Pass     4NT     Pass
                    5H     Pass     6S   (All Pass)      
          Opening lead: D6
     Playing at a club duplicate, I held the North cards when
this hand came up.  I have to admit that I got excited when
partner bid three spades in response to my take-out double. 
Roman Key Card Blackwood revealed that partner held the ace of
diamonds and the king of spades.  I suppose I could have asked
for other kings but partner was a passed hand and I thought that
a small slam was the limit of this hand so I just bid it.  I
thought for sure that distribution would provide the tricks that
were needed - partner could easily have a five or six card spade
suit.
     Declarer won the opening lead in hand with the ace of
diamonds.  Three rounds of spades took care of the outstanding
trumps as I watched with eyes wide.  The clubs came home for four
tricks and the score was +1430 for a clear top on the board.
     The discussion that followed was fun.  "Partner, I thought
you would have at least FOUR spades for your bid."  "When I made
the bid, I had four spades.  Then I saw that I had a club in with
my spades, but what could I do?"
     He did fine.  These things happen, more than anyone would
want to admit.  The lesson is to keep it together.  Don't let
anyone know that you have made a mistake.  Play with confidence
and hope for the best.  On this hand, with any lead except a
heart, declarer could even handle a 4-2 trump split.   
_______________________________________________________