After a side trip to the fifteenth century (The Second Sleep, 2019), historical-fiction master Harris returns to one of his favorite eras: WWII. In November 1944, with the German army in retreat, Londoners are beginning to relax. Until the German V2s, the world's first long-range guided ballistic missiles, start soundlessly raining down on the city. Harris tells the story of the V2 in alternating narratives starring a German engineer, Willi Graf, who assisted his friend, Wernher von Braun, in designing the rocket, and Kay Caton-Walsh, an officer in Britain's Women's Auxiliary Air Force, who is part of a team attempting to track the movable launch sites used to deploy the V2s. Crosscutting between those launching the rockets and those on the receiving end proves to be a superb narrative device, as Harris juxtaposes the engineers at work (scientists more than warriors) against their targets on the ground, "entirely unaware that the mathematics of the parabolic curve have already condemned them." Meanwhile, Caton-Walsh wields her slide rule to calculate in a matter of minutes the location from which a rocket was launched based on its flight pattern: "bearing, height, speed, and position--the integers of death." Reminiscent of the multiple stories about the Bletchley Park code breakers, Harris' novel combines fascinating technical detail with a wartime drama that finds human ambiguity on both sides of the battlefield.

This engrossing novel set in late 1944 from Thriller Award winner Harris (Munich) finds Section Officer Kay Caton-Walsh, of the Women's Auxiliary Air Force, getting ready for the day after spending the night with her married lover and boss, Air Commodore Mike Templeton, in his London flat. Then a German V2 rocket damages Templeton's apartment building, leaving Kay with minor injuries. After the emergency responders mistake Kay for Templeton's wife, and the real Mrs. Templeton learns that she was erroneously reported hurt in the attack, Templeton begins to distance himself from Kay. That personal loss, coupled with Kay's direct experience of the V2's power, leads her to volunteer for a mission to Belgium, where she and several other women are to use their mathematical skills to trace the origin of a missile's flight by working backward from its trajectory and impact point. Once on the continent, Kay gets on the trail of a saboteur. As usual, Harris brings the past to life through vivid characterizations and clever plotting. Fans of superior historical fiction will be rewarded. 75,000-copy announced first printing. Agent: Michael Carlisle, Inkwell Management. (Sept.)

A veteran historical novelist homes in on one of Hitler's last desperate hopes. In 1944, the Nazis know they're losing the war. They'd developed the V1, a pilotless drone bomb its targets could hear coming, and now its successor, which strikes without warning. The Nazis call it Vergeltungswaffen Zwei, Vengeance Weapon Two. The V2 rockets are notoriously unreliable, though. Although they're aimed at Charing Cross Station in the heart of London, any strike within five miles is considered a success. Many hit English neighborhoods, killing dozens of civilians, while others explode at launch or veer off into the sea. Chapters of the novel alternate between the two sides, specifically between German engineers and British intelligence. Twenty-four-year-old intelligence analyst Kay Caton-Walsh is in a married man's bed and survives a direct hit as floors of the building collapse around her. A half dozen people are killed and almost 300 injured. Meanwhile, German engineers work furiously to prepare missiles for launch from Belgium. Despite severe technical problems, they are under great pressure to produce the weapons in the thousands and rush them into service. The story has plenty of interesting details--for example, the bulk of Germany's potato crop that year had been requisitioned to be distilled into alcohol for use as rocket fuel. British radar can spot the V2s in flight, but "where exactly were they coming from? That was the mystery." If only the Brits could look at a rocket's parabola and calculate its point of origin....Caton-Walsh volunteers to help find out: "I'm good at maths. I know how to use a slide rule." She joins a team of women working on the problem. Readers may recognize Germany's main rocket engineer, Wernher von Braun. Though he shows necessary fealty to the Nazi cause, his secret dream is to send a rocket to the moon. And if he has to do that from America, that's another story. A short, enjoyable thriller with plenty of well-researched historical nuggets. Copyright (c) Kirkus Reviews, used with permission.