Final answer:
The letter from Norway to Denmark brings relief to Nora and Torvald as it indicates that their troubles are over.
Step-by-step explanation:
The letter from Norway to Denmark reveals that Krogstad regrets his actions and repents. He sends back Nora's bond, indicating that she is no longer in debt to him. The letter brings relief to both Nora and her husband Torvald, as they realize that their troubles are over.