Grief is sometimes akin to madness. The loss of a loved one can knock our world off its rails for a while, until we find a new way to live. But for Poppy Lang, a young widow still struggling a year after the unsolved murder of her husband, sanity seems to be growing ever more elusive. Are her gruesome dreams just that, or are they memories trying to surface? Is she really being stalked by a stranger, or is she just imagining that every passerby in a hoodie is the same man? Can she trust the police, her friends, herself?All of those questions feed the tension in Lisa Ungerís enthralling new novel, Under My Skin. This is the 16th psychological thriller from the bestselling author, who lives in Pinellas County, and one of the best yet.Unreliable-narrator thrillers have almost become a genre unto themselves, but Unger brings skill and freshness to the form. Unlike some other unreliable narrators, Poppy is the first to admit her own dubious interpretations of reality: "Sleeping and waking, dream and memory. Whatís the difference? I used to know the answer. Now Iím not so sure."Poppy and her husband, Jack, were living their best lives in Manhattan, professional photographers enjoying the success of the agency they started to represent other photographers. Very early one morning, he headed out for a run in Riverside Park; she stayed in bed, nursing a cold. He never came home. His death seems inexplicable: a big, robust guy, accustomed to handling himself in perilous situations around the world, he was beaten to death, apparently by a stranger. Gregarious and generous, he had no enemies. Robbery doesnít even seem to be the motive; Jack had a phone and $5 on him, and both were left behind, the phone smashed. Random crime, a homicide detective named Grayson tells Poppy. A year later, he canít let the murder go, but he has no real leads, either. He meets with Poppy from time to time, trying with little success to pry some new nugget of relevant information from her.Itís an uphill battle. She is back to work, but letting her staff run the business. She has dated a few new men, but, as her therapist remarks, "Setting them up to knock them down isnít dating."She feels safest in the comfort of the vast Park Avenue apartment of her longtime best friend, Layla, and Mac, Laylaís hedge-fund manager husband. Poppy has her own niche in their happy family life with two kids. "And since she and Mac got crazy rich," she tells us, "thereís no stopping them. Theyíll help you whether you want it or not. Itís annoying but kind of sweet, too."It was Layla and Mac to the rescue when Jack died, and even more so when, soon after, Poppy herself vanished."It was two days after the funeral that I disappeared," she says. "Four days after that I woke up in a hospital, remembering nothing. Even the days before Jackís murder and through the funeral are foggy and disjointed. Part of me thinks that it might be a blessing to forget the worst days of your life." Her therapist tells her that "my memories havenít come back because I donít want them." That mystery remains frustratingly unsolved, too. Poppyís only fragment of recall from those days makes no sense. She has a vivid memory of waking on the filthy floor of a restroom in a nightclub she doesnít recognize, her hair and makeup in disarray, wearing a dress she doesnít own, with a man she doesnít know waiting for her at the bar.After a year, Poppyís confusion of memory and nightmare and perhaps hallucination seems to be getting worse. Sheís always chasing sleep, and sheís self-medicating so heavily that I got a little woozy just reading about it. She knows she shouldnít and lies about it to her therapist: "I still donít tell her that I have been taking some creative mixture of Laylaís pills and mine, sleeping pills, anti-anxiety meds. That Iím not sure how many Iíve been taking. No to mention the alcohol last night. Wine. Vodka. I donít tell her that I passed out in the tub. Sins of omission."So although she believes she may have a stalker even she is unsure heís real. Then she comes home one day to the apartment she and Jack had planned to move into, where sheís still camping, barely unpacked. She finds the door open and an orchid inside with a note: "I remember you. Donít you remember me?"Add to the stalker, who now appears to be all too real, scraps of evidence (from Jackís records and Poppyís brain) that a mystery woman named Elena is a piece of the puzzle. Top it all off with a new love interest who has a strangely resonant past, plus occasional apparitions of Jack himself, and Poppyís peril escalates.Unger steers her complex plot deftly, keeping the reader as off-balance as her narrator but just as invested as Poppy is in finding out what really happened to Jack, and what will happen to her. Itís a story that will get under your skin indeed, and the shocks donít stop until the last page.Contact Colette Bancroft at [email protected] or (727) 893-8435. Follow @colettemb.