This deal was an early play problem. If I've remembered the auction at our table correctly, South's overcall was aggressive but North gave her some latitude (he may have been unclear about what slam tries were available - note to self: discuss this with partners).
But it's a play problem. At both tables, West led the four of hearts to East's king and East returned the ten of hearts, suit preference for diamonds, won in dummy (one day I'll play in a game where East gives false suit preference, reasoning that West can't be ruffing the trick or declarer wouldn't have ducked. But not yet.) Once you've placed the ace of diamonds, the ace of clubs has to be with West, so you know the hand is pretty much as in the diagram. How do you play? If you like this sort of problem, think about it before reading on.
At my table, declarer, fearing club forces if she played on diamonds, cashed one trump then tried the effect of playing a club herself. I didn't cover, so Jonathan won the trick with the ten of clubs. He read me for the ace of diamonds, but could see no fourth trick for the defence if he played a diamond - declarer could afford to ruff a heart return high - so he defended well by returning a trump. Declarer won in hand and played the king of diamonds, which I ducked, and a second diamond to the jack and my ace. I knew enough about the hand now to lead the queen of clubs: in desperation declarer tried covering it and went two off.
At team-mates' table, declarer played a diamond off dummy at trick two. East rose with the ace, so declarer unblocked the king, ruffed the heart return high, drew trumps and made eleven tricks.
Well played, but what if East ducks the diamond? You continue the suit, knocking out the ace, but East switches to a club (it needn't be the queen) and again you can't enjoy dummy's red cards. So what's the right line?
It's strangely difficult to see, but when the king of diamonds holds, declarer should change tack by playing a trump to dummy and discarding his remaining diamond on the ace of hearts. If West ruffs, declarer has two trump entries to dummy to ruff down the ace of diamonds and run the suit (or one trump entry and a club ruff, if he's carelessly blocked the spades). If West discards a diamond instead of ruffing, he'll have the same losing option when declarer next runs the queen of diamonds. And if he declines that one too, declarer ruffs out the ace of diamonds, draws trumps ending in dummy, and makes an overtrick.