Wealthy widow Mrs. St. Maugham is in dire need of a governess for her rebellious granddaughter, Laurel, who is now sixteen years old. Unfortunately, previous governesses have all fled in fear due to Laurel’s peculiar and often alarming behavior. Enter Miss Madrigal, a rather unconventional candidate who possesses no references and lacks prior experience as a governess. However, she impresses Mrs. St. Maugham with her knowledge of horticulture, leading to her immediate hiring.

As Miss Madrigal settles into her new role, Laurel quickly becomes suspicious of her strange new caretaker. She can’t help but notice that Miss Madrigal’s wardrobe is filled with brand new clothing, some still bearing price tags, and her room is devoid of personal mementos. Sensing a deeper issue behind Laurel’s troubling antics, Miss Madrigal resolves to uncover the truth, believing that the teenager’s uncanny behavior is rooted in a harrowing past. Through her interactions, the shrewd butler Maitland, befriends Miss Madrigal and warns her to secure her door at night.

Unnervingly, each night, Laurel creates chaos by igniting a bonfire in the garden, dancing around it while howling. Mrs. St. Maugham describes this odd ritual as a therapeutic process, claiming they are helping Laurel by reducing the size of the bonfire little by little. Yet, Laurel’s threats to set the house ablaze indicate that she is desperate to reveal Miss Madrigal’s secrets. This determination fuels her need to delve into Miss Madrigal’s past, which the governess resolutely guards.

In a series of elaborate deceptions, Laurel spins tales about her life, many of which are steeped in sorrow and resentment. She harbors a great deal of animosity towards her mother, Olivia, who happens to be Mrs. St. Maugham’s estranged daughter. Following a scandal involving Olivia, who abandoned her husband and ran off with a lover, the repercussions of Olivia’s actions weigh heavily on Laurel. She fabricates a heartbreaking story, claiming her father succumbed to despair and ended his life before her eyes—an assertion that Maitland later contradicts, revealing that the truth was far less dramatic, as he died from complications related to alcoholism.

Adding to the intrigue, Laurel recounts a harrowing incident involving an alleged attacker in Hyde Park, just before her mother’s marriage. However, the truth surrounding that event remains shrouded in uncertainty, as Mrs. St. Maugham refuses to allow her daughter to seek medical examination or police questioning, believing firmly that Olivia is unfit to be a mother.

Over time, Miss Madrigal begins to develop a bond with Laurel. They indulge in sketching under the sun and challenge each other to playful tennis matches. Slowly, Miss Madrigal learns to dismiss the bizarre narratives spun by Laurel as mere fiction. Life takes a turn when a telegram arrives from Olivia, expressing her intention to visit and see her daughter. The revelation shocks Mrs. St. Maugham, who, despite her animosity toward her daughter’s choices, still carries affection for her. Laurel, realizing her mother’s impending visit, mysteriously disappears, prompting a frantic search by Miss Madrigal and Maitland.

Olivia threatens legal action to reclaim her daughter, intensifying the already fraught atmosphere. Amid this turmoil, Miss Madrigal finds Laurel by the beach, igniting a moment of emotional vulnerability where Laurel admits to her inner turmoil through tears. Her story of distress is matched by Maitland, who shares his own tragic past, revealing how he once ran a small hotel where the St. Maughams stayed, only to suffer a surreal loss in a car accident.

Underneath the surface, Miss Madrigal grapples with her past, which she strives to conceal. During a village trip with Maitland, she discovers Laurel rummaging through her belongings and coming across a mysterious locked briefcase. Intrigued, Laurel uses tools to unlock it, revealing paints and a palette marked with the initials C.D.W.

On one fateful evening at dinner, Laurel confronts Miss Madrigal about the initials, only for Miss Madrigal to deflect, stating they belong to her sister. However, as Judge McWhirrey arrives for lunch, Miss Madrigal’s reaction speaks volumes, indicating a history entwined with crime and guilt. The judge inadvertently exposes fragments of Miss Madrigal’s own dark past surrounding a sensational murder trial involving a youthful defendant named Constance Doris Wakeland.

In a moment of remorse, Laurel offers a heartfelt promise to keep Miss Madrigal’s secret, although her curiosity is intrinsic to her need to control her reality. Faced with the potential loss of Laurel to Olivia, the stakes rise and compel Mrs. St. Maugham to engage with Judge McWhirrey. Tension builds as she learns remnants of Miss Madrigal’s past, forcing her to confront uncomfortable truths.

In a pivotal discussion, Miss Madrigal declares the necessity for Laurel to reunite with her mother. To everyone’s shock, Laurel overhears the discourse. After her mother arrives, Laurel takes a stand, declaring her readiness to leave with Olivia while publicly thanking Miss Madrigal for her support, signifying a transformative shift in her narrative journey.

As Mrs. St. Maugham invites Miss Madrigal to remain, she accepts, choosing to construct a vibrant garden and shape a brighter future. The sentiment of accountability lingers when Mrs. St. Maugham inquires about Miss Madrigal’s past, leading to a surreal final exchange that leaves readers pondering the ghosts of truth buried deep within; and ultimately, Miss Madrigal cryptically remarks, echoing the enigma of her history: “If I did not tell the many learned men at the top of their profession who questioned me all those years ago, I certainly will not tell you.”