Baron Munchausen (or a descendent) claims to have held the South hand and heard his right-hand opponent open seven spades.
The Baron reasoned that East was a sound bidder, so the only hand he could have, given South's holding, was a singleton club ace and 12 solid spades.
That meant that West was void in spades and would not know what to lead against seven no-trump. Full of his customary bravado, Munchausen made the bid of 7NT and was doubled on his right.
The spotlight was now on West, who was somewhat dazed by an auction that he, like the rest of the world, had never heard before. The Lightner double, asking for an unusual lead, did not seem to offer any guidance in this situation.
Leading one's long suit against no-trump is standard, but the double demanded a non standard lead! East would not have doubled holding 13 spades, so he had to have an ace. BUT WHICH ACE???
So West should have led a club, which would have given the defense 13 tricks. Instead he did not reason correctly and led his shortest suit the diamond jack!!
Munchausen, finding exactly the dummy he needed, quickly gathered in six diamond tricks and seven heart tricks.
''That is new to me,'' declared Munchausen thoughtfully. ''A grand slam for either side that depends on the opening lead.''