The bidding: South, with 14 points, opens one diamond. West overcalls one spade. This is both lead-directive and suggestive of a suit to compete with.
North has the unbid suits and makes what is called a negative double. Sometimes, the negative double just shows four cards in the unbid major. North does not need clubs if he can run to partner’s original suit or notrump.
Here North has five diamonds and five hearts. He doubles and if partner bids clubs, he corrects to diamonds.
In this case, East is weak and distributional and raises partner to four. East does not expect his partner to make, but with his void, the penalty will be slight. The goal is to stop opponents from finding their proper contract.
South passes because things are too high as far as he knows. However, North bids five diamonds and South corrects to five hearts.
Five hearts by South
The opening lead:
The ace of spades
South loses a spade and a diamond making his contract with a spade lead and spade continuation.
Five hearts making for+450.
Note: The killing lead, quite the gamble, is a small diamond. East ruffs and returns a spade. West gives East another diamond ruff setting the contract by one.