“
You’re a series detective now. You have a canon. Which means”—he spun his fingers in the air—“ you’re due a nemesis.” “A nemesis?” I chewed the word. “Every great detective has one. Your equal in wit, skill and mind. Which, for you, well . . . that’s not the point. Do you see? Moriarty. Mr. X.” Arguably, Moriarty as Holmes’s foil is overstated by modern adaptations. And Mr. X, too, was only in the final Poirot novel. In the written works, these villains are one-offs, not the stuff of ongoing pursuit. But their legacy is not in the cat-and-mouse, it’s in what they take from the heroes. Holmes compromises his rationality, and Poirot, to put it simply, switches sides. A nemesis isn’t about matching wits or being equal. It’s about making the detective less.
”
”
Benjamin Stevenson (Everyone This Christmas Has a Secret (Ernest Cunningham, #3))