South begins by leading the ace of diamonds, which, depending on what the opponents discard, opens a possible finesse of North's jack of diamonds.

Next, South passes the lead to North with a spade that North trumps.

North then leads the last heart, and South discards the 10 of clubs.

With the lead of the last trump and then the ace of clubs, the defenders are presented with an insurmountable dilemma.

East must hold two diamonds or South takes the last two tricks in the suit by discarding a spade.

However, in order to hold on to two diamonds, East must discard the jack of spades, which in turn would force West to hold the queen of spades.

Since West also needs the queen of diamonds and the jack of clubs to avoid losing a trick, a discard from any of the three suits will allow South to win all of the remaining tricks by an appropriate discard.
 

What do you open as East?

A gambling 3 No Trump usually promises a solid 8-card minor and an outside entry.

Too strong for a pre-empt, possibly, so a sensible 1 Diamond.

South may be tempted to bid 2 No Trumps, to show both majors, but maybe too weak!

West bids 2 Diamonds, showing a weak hand with Diamond support 

North, with this powerhouse, Doubles.

East is now in competitive mode and bids 3 Diamonds (maybe looking at the vulnerabliity)

South now bids 4 Hearts - the void in Diamonds is a real feature of the hand.

North is excited, looking for a slam, and bids 4 No Trumps (Roman Key Card Blackwood, asking for Aces)

South realises the importance of the Diamond void and skips the usual 5 Diamond response (no Aces) and jumps straight tro 6 Hearts.

West and North both Pass, and East thinks....

6 Hearts is 1430, 7 Diamonds down 5 Doubled is only 1400.....

They bid 7 Diamonds. It is duly doubled and goes down 5, but East has saved the day!