West's double serves two purposes. First, it is a negative double, to show a 4-card spade suit. Second, if East takes it as a lead-directive double, that's fine, too. With the A-Q-J behind the 1♥ responder, you're expecting a couple of heart tricks should North play the hand.

Although South bid 1♥, it's possible South also has four spades - but by bidding 1♠ that's showing no extra values. Jumping one level and bidding 2♠ is a reverse, showing a huge hand. If South did not have four spades also, then 3NT would be South's bid (8 HCPs plus North's 17+ HCPs is a NT game).

South has a strong enough hand that South can bid a reverse (jumping in spades) to show four of that suit and 17+ HCPs. If South had five spades, South would have opened 1♠ - so North knows there's a 4-card suit there.

There's some question as to whether all Souths will take North to 3NT, but if you're not up for an adventure you're sitting at the wrong table. South won't make 3NT with a heart lead, but it's North that is playing the hand.

North can make 3NT by playing the clubs for a 3-3 split. When you lead the 10♣ (as soon as you get the lead) you can't afford to play low from dummy because you have limited entries to dummy. Overtake with the J♣, then if the opponents duck play the Q♣. They can't afford to duck a second time, so when you get back in you can play a spade to finesse the K♠ - and when getting to dummy play the A♣ and remaining clubs. If you're in the dummy, go ahead and play the A♣ on down. You'll have the entry with a diamond later to get back there and you can make five clubs, two spades, either two diamonds or a diamond and a heart.

Most NLMs playing West will open this hand starting with 1♦ - then try to jump or come up with some other bid later on to show the strength of this hand.

A better opening bid with a 4-loser hand like this might be 2♣. This is a game-force for most partnerships, so you'll end up in either NT or diamonds down the road. . .and it shows the strength of your hand right away to East - who in this case has 14 HCPs and a 6-loser hand. While it is true, you don't have 22+ HCPs, you do have 8 quick tricks in diamonds - and 17 HCPs (plus 5 for a void) will justify a 2♣ open here.

Expecting to play in a diamond slam once partner shows either aces or controls (depending on your 2♣ convention responses), once you find a heart fit, the score will be better in the major suit. A hand that makes 6♦ and 6♥ should be played in the major. Keep in mind there's no bidding convention that works all the time; but here, controls show exactly what East has. With five control points, that means either a combination of A-A-K or A-K-K-K (with Aces counting as 2 control points and Kings as 1).

West knows it's not possible for East to have three kings, so West knows right away both missing aces and a king are in East's hand. That should be enough to bid onward. Can you bid 7♥? It's tricky. The reason it can make is because of East's doubleton club, supported by West's A♣, and with the hearts only missing the Q♥ it can be finessed by either direction. There's yet to be a well-defined bid that shows the 10-9 in addition to the K♥, or the J-8 with the A♥ - so the 7-level will be strictly for the adventurous.