At first i thought 5♣ should win the bidding because of their one suit dominance but after carefull consideration i think N-S could win with 5♠ and my bidding would go as such: 1♠-2♣-4♦-5♣ 5♠-All Pass But of course no one know each others cards so E-W would probably win unless N has guts. The 5♣ can be defeated because South will play first and will play A♥, and then lead a low spade for parnter and he will use both aces to defeat.