South (the expert) opened 41 and rebid Three No-trumps over the response of 22. North, quite intelligently, tried 45, strongly suggesting that he had no red suit controls. With both the vital aces, South went on to 46 (perhaps Five No-trumps might have been better?) and West led a trump against the slam.
Pursing his lips slightly, South considered dummy. There were 13 top tricks in spades, clubs or no-trumps if the club suit behaved. Perhaps overestimating the strength of the field, he decided that his best chance of a good score lay in finding a bad club break. Then simply drawing trumps and hoping for the best in clubs would lead to defeat.
Inspiration came. He drew just two rounds of trumps, leaving the king in dummy, then cashed the queen of clubs and followed with a finesse of the ten. If East was able to ruff, he reasoned, that would be the last trick for the defence while, if East won, the king of spades would be an entry for the remaining clubs.
Alas, East won with his jack of clubs and unsportingly was able to return a club. South ruffed high (discarding would have led to immediate defeat) and suddenly realised that there were now only three good clubs on which to discard his four losers. He had to finesse the queen of diamonds at the finish, and was one down.
Game all; dealer East