How do you describe a long, long suit?

Jon Bon Jovi reputedly said, "Success is falling nine times and getting up 10." Today's deal features something very rare: a nine-card suit. It was played six times in a duplicate in Florida. With East-West vulnerable, South opens one heart, and West passes. What should North do?

The normal response with this hand is five diamonds. Four of the six players in that duplicate did just that, and it ended the auction. Three made the contract, losing two spades. One North went down, I cannot imagine how.

Two Norths bid only three diamonds, a weak jump response. One South sensibly passed - misfits are miserable - but it did not work well here. The second South rebid three no-trump and got a top.