Undone (Will Trent, #3)

by Karin Slaughter

She caressed his cheek with her hand, thinking not for the first time that it was a miracle that something so perfect had come out of her imperfect body.

“My mother always told me there’s a fine line between never and always.” He looked confused, and Sara explained, “Once you do something bad, it’s easier to do it again the next time, then the next time, and before you know it, you’re doing it all the time and it doesn’t bother your conscience.”