The epigraph to Caroline Kraus’s first book, Borderlines: A Memoir, is a quote from Gerard Manley Hopkins: “O the mind, mind has mountains; cliffs of fall/Frightful, sheer, no-man-fathomed.”

Caroline Kraus deftly plumbs the depths of those cliffs and mountains in her new memoir: not only the depths of her own mind, but also, more intensely, the mind of Jane, the young woman she befriends when she moves from St. Louis to San Francisco. Kraus leaves Missouri about a year after her college graduation and shortly after the death of her mother from cancer. Instead of the new beginning she had hoped for, working at a bookstore and studying film at Stanford, Kraus’s new life becomes quickly ensnared by Jane’s never-ending needs.

The narrative segues back and forth between Caroline’s childhood and young adulthood in Missouri and her time in California. Kraus’s weaving of past and present is effective and never choppy; she has carefully crafted each chapter to flow smoothly into the next, mastering a technique that would fail in the hands of a less adept writer.

Caroline meets Jane at Sorrell’s bookstore in San Francisco, which has been patronized by literary and musical greats like Jack Kerouac and Joan Baez. She figures if Joan Baez liked Sorrell’s, so would she: “It was a place that seemed ripe with possibility; I was already envisioning my new life as a writer, filmmaker, and all-around free spirit.” But like many visions of new life, Caroline’s San Francisco dream does not fulfill her fantasy.

Jane is a compelling figure to nearly all who meet her; she has a way of making everyone feel special, like the only person in the room, although Caroline finds it mysterious that a few of her co-workers at Sorrell’s are immune to Jane’s charms. Caroline is quickly taken in by Jane and finds that Jane’s mental and emotional needs are bottomless. Jane claims to have been sexually abused as a child, though her family won’t believe her, and she sucks her thumb like a child. She also steals books as well as cash from the register at Sorrell’s.

The two become best friends, then roommates, and, briefly, lovers. Caroline is completely consumed by Jane and her needs for money, love, and comfort, and the friendship becomes more and more strange. The reader wonders why Caroline keeps hanging on to Jane, and it is at times frustrating to see her repeat the same behaviors in the friendship. Eventually Caroline, who has been providing for both of them financially, has no money left, though it takes her months to realize how much she is being used. She sees herself as Jane’s rescuer, never realizing she is becoming one in need of rescue herself.

Jane’s manipulations and the death of Caroline’s mother are intertwined in the narrative to show Caroline’s own need to be needed; unable to save one life, Caroline tries to save the other. Finally, after three years of manipulation and lies, Caroline realizes Jane’s salvation is not her responsibility. Caroline is able to extricate herself from Jane’s grasp and moves East, although, in a puzzling turn, allows Jane back into her life briefly when she is living in New York City. She says of her friendship with Jane, “Our collision was the worst possible train wreck, yet the experience has delivered me.”

This is a fascinating book that delves into elements of grief, troubled minds, and the freeing of oneself from the sorrows of the past. Borderlines is a book you won’t want to put down.