Note 1: (there must the cure be found)
Where the wound had been given, there must the cure be found if anywhere...
This sentence echoes Darcy's motives for searching for Wickham and Lydia in Pride and Prejudice:
The motive professed, was his conviction of its being owing to himself that Wickham's worthlessness had not been so well known...He called it, therefore, his duty to step forward, and endevour to remedy an evil, which had been brought on by himself. (Mrs. Gardiner in a letter to Elizabeth Bennet).