A struggling private investigation office, a stressful balancing act between surveillance and teaching at a martial arts school, and on top of that, an opaque ex-mercenary as a tenant - Rowan Lockhart's fresh start in her hometown of Edinburgh after her divorce from her Japanese husband is anything but smooth. Just when she needs it, a letter from Captain Finn Macrae arrives, asking her to monitor his wife. But before Rowan can get in touch with him, Macrae is dead: suicide. He allegedly revealed military secrets and was supposed to be held accountable for it. Although the evidence of his guilt is overwhelming, Rowan begins to investigate on behalf of her sister, unwittingly stirring up a dangerous hornet's nest with fatal consequences not only for Rowan.