When I saw the 3♠ bid appear I feared it was one of those very frequent times a partner was overbidding. But that actually wasn't the case at all, partner very much had what he should have.
So now the play. Let's assume they start leading ♦ King and switch to a High club. Not obvious, but quite reasonable. The ♦ Jack would then hold the trick, and another ♦ would seal the fate of the contract. Losing a ♣ a ♥ and a ♠ is inevitable for down one.
But as it went, it was ♦ King, ♦ Ace and a ♣ to the Ace and now East played a ♣ to partner's king...
So now partner STILL has two losers, but there is a very elegant play not to lose two more tricks. It involves 4 Queens...
Anyone?