Herbert is astonished to hear the story of Magwitch the benefactor, but he's a real trooper, helping Pip think through this crazy scenario.
Pip tells Herbert he can't take Magwitch's money, and he wants to repay the convict for the money he's already given.
Herbert tells Pip to leave England with Magwitch, to take him out of harm's way. Good idea.
The next morning, Magwitch comes over for breakfast, and Pip asks him to tell his life's story. Magwitch gladly acquiesces, but he makes it known first and foremost that he's paid off every debt and every crime he's ever committed.