Breaking the Dark by Lisa Jewell

In her most imaginative novel yet, #1 bestselling author Lisa Jewell (None of This Is True) launches the Marvel Crime series of thriller books for adults with an original story starring the private detective Jessica Jones.

Meet Jessica Jones: Retired super hero, private investigator, loner. She tried her best to be a shiny spandex crimefighter, but that life only led to unspeakable trauma. Now she avoids that world altogether and works on surviving day-to-day in Hell’s Kitchen, New York.
The morning a distraught mother comes into her office, Jessica would prefer to nurse her hangover and try to forget last night’s poor choices. But something about Amber Randall’s story strikes a chord with her. Amber is adamant that something happened to her teenage twins while they were visiting their father in the UK. The twins don’t act like themselves, and they now have flawless skin, have lost their distinctive tics and habits, and keep talking about a girl named Belle. Amber insists her children have been replaced by something horrible, something “perfect.”
Traveling to a small village in the British countryside, Jessica meets the mysterious Belle, who lives a curiously isolated life in an old farmhouse with a strange woman who claims to be her guardian. Can this unworldly teenager really be responsible for the Randall twins’ new personas? Why does the strange little village of Barton Wallop seem to harbor dark energies and mysteries in its tight-knit community?
A mother’s intuition is never wrong. And Jessica knows that nothing in life is perfect—not these kids, not her on-again, off-again relationship with Luke Cage, and certainly not Jessica herself. But even as she tries to buy into the idea that better days are ahead, Jessica Jones has seen all too clearly that behind every promise of perfection trails a dark, dangerous shadow.