" that everyone has a capacity for evil. And we’ve all seen it, and done it, even if we think we haven’t—there’s the slight in conversation that wounds another person, the words we know will cause pain to a loved one but we utter them anyway, and the unkindness that could have been avoided. But then there are people in another league, if you will, people who are capable of so much more, who harbor an evil so deep it scars all our souls. That kind of darkness can lie dormant, as if in a barren desert, but then . . . but then circumstances change to allow their evil to become truly, truly terrible, a boiling storm that encompasses all in its wake. "
― Jacqueline Winspear , Journey to Munich (Maisie Dobbs, #12)