How does Torvald respond to Krogstad's second letter?

When Krogstad's second letter arrives, Torvald does a complete turn around. The revelation that his wife has paid back the debt and saved him changes his mind about his wife. Torvald's response is actually revolting based upon the things he said to Nora only moments earlier, as suddenly the shifty, dishonest woman he just threatened turns into a heroine. Even worse, Torvald sees himself as generous in giving her his forgiveness.