South won with the queen and tried a club to the king.
He returned a club, and South won with the queen.
East won with the queen, and led a low club.
She led a heart, on which West had to play low, and won with the queen.
A heart was returned, and South won with the queen.
She won with the queen and led the club king.
He then led a heart, and won with the queen when East, in his turn, played low.
It was then safe to return a heart, and West won with the queen.
South would have won with the queen and followed a similar path.
South allowed East to win with the queen and was in control.