Withering on the vine

Playing in a mini-tournament (12 boards) on the Internet at BridgeBase Online, it goes Pass Pass 2♥ and you hold:
♠Q 8 7 ♥A Q J 4 ♦K 4 ♣K Q J 8.

You overcall 2NT. The opponents are now silent. Partner bids 3♠. What is that?

You bid 3NT, all pass, West leads the ♠6, and these are the combined hands:


Your right-hand opponent plays the ♠J and you win the queen. To have any chance, you must win some diamond tricks, so you cash the ♦K and it goes low low queen! Well, four diamonds is a start at least, so you lead your ♦4 to the ♦9 and RHO wins the ♦10! Your good diamonds are now stranded!

Here are all four hands.


The opponents take one diamond, four spades, one club and still get a heart in the end for down three and 9.18 IMPs for East-West (Kate and me).

After the deal is over, partner tells you he was trying to transfer to diamonds with his 3♠ bid. Playing online with different partners is always dicey, isn't it?

You can see all the results for this board here.