Very interesting point which I don't has been covered much (and the author agrees

Not too hard, you'll probably know once you've got it. Merry Christmas!
The bidding was aggressive, but both North and South love vul games and back themselves to make sub-25 3NTs when all the points are in one hand.
1♣ showed 4+, and as EW are playing a weak NT system, if East is balanced he will generally be in the 15-17 range.
The play begins with the lead of the 3♣, to the 9, Q, A.
As South needs a heart trick even if spades break, he begins with a heart to the Queen and Ace.
East returns the 4♣ to the Jack, 7, deuce. Plan the play!
EDIT: solution two posts below

The bidding was aggressive, but both North and South love vul games and back themselves to make sub-25 3NTs when all the points are in one hand. 1♣ showed 4+, and as EW are playing a weak NT system, if East is balanced he will generally be in the 15-17 range. The play begins with the lead of the 3♣, to the 9, Q, A. As South needs a heart trick even if spades break, he begins with a heart to the Queen and Ace. East returns the 4♣ to the Jack, 7, deuce. Plan the play!