Negative Doubles

Board 3
South Deals
Both Vul
♠Q 3
♥K Q 7 6
♦J 10 8
♣A Q J 2
♠A J 10 9 7
♥10 8 4
♦A 6 4 2
♣7
N
WE
S
♠8 6 4 2
♥9 5
♦5
♣K 8 6 5 4 3
♠K 5
♥A J 3 2
♦K Q 9 7 3
♣10 9
WestNorthEastSouth
   1♦1
1♠2Dbl32♠4♥4
All pass   
  1. S pens 1♦
  2. W overcalls 1♠
  3. E doubles to show his 4 card ♥ suit
  4. A competitive bid of 2♠ by E supporting his partners overcall is ignored by S who bids to game. It won't be easy!
4♥ by South