Last week we were considering a defensive position.
Playing 3rd and 5th leads, the lead of the Two of hearts seems odd, since on the prevailing vulnerability partner would very likely have bid 4 Hearts with 5-card support. If you are playing with an excellent partner, you must consider that he may be aware that dummy might show up with short hearts, and be using his heart lead as a suit preference signal rather than, as is most common, a count indication.
If that inference is correct, he is trying to show you some honor in clubs -- looking at your hand and at dummy, that must be the Ace.
Another thing to consider is that if declarer has that Ace, your chance of defeating the contract becomes remote, since you may lack the time to establish a hypothetical club trick (if partner has the Jack, i.e., if playing a club right now is disastrous).
All things considered, your best shot to defeat the contract is to play the King of clubs, trying to score a club ruff.
Declarer's hand was:
Some people would consider this 4 Spades bid by South too aggressive. Whether or not this is the "right" bid is neither here nor there. As I pointed out, you cannot base your reading of the opponents' actions on your own beliefs. When you are in doubt, bidding 4 Spades over 4 Hearts is most often a good idea.
My advice is: think out of the box and always look for your best chance of defeating the contract, no matter what.