CONTRACT: 4 South
OPENING LEAD: A (denying the king)
Four possible losers: one spade two diamonds and one club.
Line of play: establish the diamond queen in dummy to discard the losing club.
Trick 1 W: A, 5, 6, 3
Trick 2 W: 2, 4, Q, A
Following the club shift by West, declarer cannot avoid four losers: one spade, two diamonds and le club king.
Remark: if West continues with a diamond at trick two, he will establish dummy's queen for a club discard in South and declarer will make his contract.
The contract is set one trick.
The defense takes four tricks: one spade, two diamonds and the club king.