Amidst a boom in indie-published UK crime fiction of high quality, Andrew Lowe’s series featuring homicide cop Jake Sawyer ranks at the apex. Sawyer is a mythically appealing protagonist, super smart yet unconventional, a martial arts devotee yet wracked by traumas from a terrible family past. In “Cruel Summer,” the seventh in the series, our hero finds himself seconded, after barely escaping sacking in his Peak District domicile, to London, to assist the Met with a baffling series of truly horrific murders. The author is a superb stylist, fluid, pacey, and atmospheric, with an ear for sharp dialogue, and in this book is at the height of his prowess. The book powers along relentlessly and the denouement is a wonderment of adept wrap-up. Throughout this main plot trickles a subplot of various groupings of evildoers intent on bringing Sawyer down, a continuing thread in the series, and at least in this novel, this diversions feels a little like that, a diversion, but I take it on trust that in the next volume or so, all will intersect gratifyingly. Cruel Summer is a rocket of a mystery, best consumed in one armchair sitting.