At a certain point in a "tortured detective" crime series, the increasingly outrageous plot and character developments necessary to sustain the novels' ongoing mythology becomes a danger to the whole enterprise. We as readers love our heroes — alcoholic Oslo cop Harry Hole, in this instance — but the incredibly gifted Nesbø must be wondering how much longer the fan base can suspend disbelief. Aspects of "Knife" REALLY push it, but this is Harry we're talking about. And if he can by God return from opium den addiction, and a hellish thirst for liquor, and reconcile yet again with his beloved Rakel — or get thrown out by her — and continue to thwart the remarkably vital 70-something serial rapist/murderer Svein Finne, well, I'm willing to saddle up for the ride. There's some crushing developments this time out and a LOT of ridiculousness, but Nesbø and Harry somehow continue to keep me loyal.