Angie Voorster is just seventeen when Katharine Noel's stunning Halfway House opens. A star athlete, Angie has a bright future, she does well at school - even writing papers for extra credit - and she has many friends. College is an absolute surety, and she is determined to qualify for the regional swimming team.

But one afternoon at a local swim meet, Angie begins to act strangely, exhibiting the first signs of an irrevocable emotional imbalance. At the start of the boys' race, she dives headlong into the pool, "a high, arching dive that makes an almost imperceptible splash," and swims straight to the bottom, convinced that she doesn't have to breath underwater.

Her father, Pieter, dives to rescue her, but Angie surfaces a broken girl. Over time, Pieter, Jordana, her mother, and Luke, her baby brother are driven to the darkest depths, left to pick up the pieces and battle Angie's unending illness. At first, she is admitted to the hospital and diagnosed as schizophrenic, but the first anti-psychotic prescribed to her makes her even more psychotic.

She spends some time on a rehabilitative farm, "where you aren't allowed to say words like psycho or crazy," then returns home after several months, somewhat stabilized but a shell of her former self. Her face puffy from drugs, she constantly battles tiredness and lethargy, becoming a chain-smoking, needy, dependent girl who "just longs to keep her thoughts on track."

Angie's parents, never clear whether they are actually doing the right thing, attend to the rigors of her everyday life – checking that she takes her meds on time and driving her to the clinic for blood work. She really does try to hold it together, until on a weekend trip to Harvard to visit her boyfriend, she goes off the rails.

Back into hospital she goes, then home again, then to a group house for the mentally ill, where she drifts among her roommates, forming fractured and loosely knit friendships. She gets odd jobs, goes off her medications and loses them. Off the meds, she picks up men she doesn't know, gives all her money to panhandlers, buys extravagant and useless presents, and destroys possessions.

It is a sad, lonely, insecure existence. All Angie wants is a life of coherence and a little grace, where food can actually taste like something and where thinking about sex doesn't make her feel exhausted and sick. She is tired of feeling simultaneously exhausted and ramped up – depression connecting her and time feeling like a spiral line.

Author Katharine Noel's strength is her ability to portray Angie's inner turmoil, spanning most of her young adult life and its world of bleak, stark and uncompromising hospital wards where there is little to do but smoke and vegetate in front of the television. The author excels in showing Angie's conflicted and obsessed inner life: "her thoughts like water bugs, skating rapidly over the surface of water – a sink trapped and blind and hitting the angles. "

After Angie's first breakdown, Pieter, a renowned cellist, finds solace in his music and begins to draw away from his wife, "feeling literally as though he were being unhinged, the parts of him gently, stealthily moved apart." Jordana embarks on an affair then immerses herself into frenzied projects like boxing up donations for Goodwill, then losing heart. The fear she feels for Angie wears down to an anxiety so persistent "it almost feels like she'd always had it." For his part, Luke seeks the comfort of his neighbor, Khamia, escaping the trials of his own house a relief. Later Luke comes to champion Angie, his love for his sister so protective, so fiercely loyal, yet also tinged a guilt that he should have done more for her.

The drama comes from Noel's ability to intuit the everyday, where mental illness has unfortunately become just a fact of life for this family. It is a testament to the nature of the tragedy that, over the years, the Voorsters fail to find that much comfort from each other.

Angie ends up a drifter - not ill but not really functioning, dependent on lithium for her emotional well being. Most of the things she once valued in her life have been lost, left behind, or destroyed. At novel's end, she is a woman on the cusp of middle age, contemplating a new life in California, homesick for the girl she once was, her longing for what might have been so deep and unanswerable that it absolutely "takes her breath away."