NORTH
 9842
 Q
 KJT982
 42
 T7
 987
 43
 K98765
  AK53
 JT6
 Q765
 JT
  QJ6
 AK5432
 A
 AQ3
Dealer: South    Vul: NS   MP Scoring

West

3
Pass
Pass

North

3
3
Pass

East

Pass
X

South
2
3
Pass

 How to Play a Doubled Contract 

For many pairs, South's pass over 3 is ambigiuous, isn't it?
Does 3 show 4+ cards?
Does the pass of the double show some number of spades? Desire to penalize? Optional?

East led the J and declaring North won the A.
The Q was unblocked, A won, and North's 2nd club discarded on the
A club was ruffed and a spade advanced.
What was East to do?