Mrs Sally Gilmartin is not in fact a chocolate box Cotswolds village pensioner in the 1970s, she is beautiful and resourceful WWII British spy Eva Delectorskaya. Well, she is both, of course, at different times of her life, as a split narrative written from the point of view of Sally’s twentysomething daughter in the ‘70s linked with a third person account of Eva’s wartime exploits, explains. Boyd chucks a fair bit in, much of it spy-level misdirection, with subplots skulking in doorways appearing to leer suggestively at Eva or her daughter but then never actually coming to much: German ex-husband. A bit of Baader-Meinhof terrorist chicanery. A lot of time spent in Canada. Spy authors like love stories: they emphasise betrayal and duplicity. When Ben MacIntyre was researching Agent Zigzag, his excellent book on real-life WWII double-agent Eddie Chapman, he was phoned by an anonymous, cultured elderly woman. “Eddie Chapman,” she told him over the phone, “was a grade A shit.” It’s a pity Eva never had the chance to read this, since it might have helped her spot that her boss Lucas Romer was a right royal wrong’un. More than once Boyd spells it out: you never trust anyone. Why Eva should fall for her boss is, then, is simple: the plot requires it. The plot also needs him to come a cropper, and he does. Nazis used to give German high-ups suspected of plotting against them the medieval option of killing themselves. Romer is of the same school and his fate in a Knightsbridge house is satisfying enough. There are a couple of fabulous set-pieces, one involving a pen, a corrupt cop and a sticky end in New Mexico. There are also clunks – the narrative structure, for example (Eva was not only a terrific secret agent, she also writes with the skill of a prize-winning novelist). And it needs a conjured-up academic to explain – well, theorise – over exactly what Romer’s role was. But it’s hard to carp at a story that clips along and does you the great courtesy of making you feel just about intelligent enough to keep up. Meanwhile Sally is left scanning the horizon for more intruders into her secret life.