Cohen's sensitivity to mental instability, a subject matter that dominates much of this tale, separates They All Fall Down from the current crop of contemporary British mysteries. Hannah Lowell finds herself ensconced in The Meadows, an exclusive private sanitarium that peddles niche therapy for women known to be a high suicide risk and who have attempted suicide before. In an effort to assuage the demons of the "baby that might have been," Hannah takes daily art therapy classes with Laura, a sensitive and cosmopolitan psychoanalyst.

Hannah is lamenting the death of Charlie, the first person she met at The Meadows. Apparently, Charlie suicided. Hannah, however, is convinced that her new friend would never have taken her own life. According Dr. Oliver Roberts (a sort of new-age guru and sage), Charlie had deeply buried internal wounds and a "deformed soul." With her days passing in a "black fug," Hannah tries not to let herself think of her baby, Emily, or what really happened to Charlie. Laura worries about Hannah because she seems unable to process Charlie's death. Hannah is convinced that there's dirty work afoot: "it could be Dr. Roberts or any one of them"--Frannie, Odelle, or even vulnerable Stella. Hannah also has a sense of unease, of being watched

Cohen writes the action from Hannah's point of view: her efforts to assimilate back into the real world, the quivering anger she has over the sleeping pills she takes every evening, and her reaction to Charlie's "to-do list" written while she sat on the floor with her back against the radiator. Crumpled now from being folded and unfolded, the list gives the first clue in Hannah's efforts to vindicate her friend. Dr. Roberts remains polite and interested, but his missives are skin-deep. When Hannah's parents, Mr. and Mrs. Chadwick, arrive and accuse Hannah of being somehow complicit in their daughter's death, Hannah tries to impose on the Chadwicks her own version of events--that someone deliberately harmed Charlie--despite knowing that it "just doesn't align with the facts." Hannah sense danger, just a week after Charles's death. Even her fellow patients, Odile and Frannie and Nina, can't shake off the dream that everything is smudged.

Crucially, there is another point of view. Hannah's mother, Corrine, has been left to shoulder the burdens of her tired and emotionally overwrought daughter as well as assuage Danny, Hannah's flaky husband. Corinne assumed that Hannah would dust herself off after a period of grieving, but now she thinks her daughter is going crazy. When Corrine visits at The Meadows, she pleads with Hannah to let Charlie go. Obviously angry and possibly ill, Hannah stubbornly tells her mother that she can't believe that Charlie killed herself.

Ricocheting between Hannah and Corrine's voices (and, to a lesser extent, Laura's), Cohen reveals her protagonists' tortured states of mind, capturing their internal struggles and the secrets used to shore up their respective versions of the events that lead up to Hannah's incarceration. All of The Meadows patients must come to terms with the fact that there may be a murderer among them. Perhaps Dr. Roberts is nothing more than a psychopathic charmer without a trace of conscience, ripping through the London medical establishment, his actions holding on to the macabre promise that Hannah has always known firsthand.

Corrine turns to Steffie Garitson so she can make sense of the unexplained incidents that have kept her awake night after night: the time Hannah threw Danny out; the bust-up with Megan; the doctors' appointments and scans that seemed to fall when Danny was away; and finally her trip to Tunbridge Wells, where she learns that a daughter as disturbed as Steffie must have affected them all. From the deceptively bucolic grounds of The Meadows to the rundown suburban backwaters of London, the novel seethes with a sense of menace: Corrine's nugget of hatred, "dense and hard and solid as a bullet;" the ghost of Charlie; Hannah, whose fate is inexplicably sealed as she floats around in a cloud, trying to ignore the tiny worm of anxiety eating its way through her gut.

In many ways, the novel is quite predictable. What makes Cohen's tale so readable is how she presents the dark shadows lurking on the edges, originating from Hannah's own private nightmares. From the family fallout and Corrine's guilt to Hannah's anxiety over living a dishonest life, Cohen unfurls the burden of family secrets, murder, and the fears that a treasured mother/daughter relationship is in danger of being ruined.