Opener's Rebid after Partner's Negative Double 13

Opener's Rebid after Partner's Negative Double 13

Question:

You are South. Matchpoints. None vul. 

You hold: 

Q6543
AQ2
K102
Q8

What is your next call on this auction:

  West    North    East    South  
   1spades icon
2hearts iconDbl Pass?

Answer: