Set in 1884 London, this volume follows Emma M. Lion, a young woman of modest means who owns a house called Lapis Lazuli in the eccentric neighborhood of St. Crispian's. Emma's close circle includes Niall Pierce, a photographer who rents her adjoining studio; the Duke of Islington, her unofficial guardian following news reports that linked the two as guardian and ward; and Hawkes, the neighborhood's enigmatic vicar. As the volume opens, Emma and Pierce have recently acknowledged romantic feelings for each other, though their courtship remains secret.
The narrative begins on May Day, when the annual fair in Baron's Square draws the neighborhood together. Emma banters with Islington about the flood of letters prompted by their publicized connection, and she shares a private moment with Pierce, who admits he is pleased whenever he catches a glimpse of her. The fair's drama centers on a boxing ring, where a brutal strongman injures several challengers. The Reprobates, a gang of loyal parishioners, pressure Hawkes to intervene. He reluctantly enters the ring, displays surprising skill, and knocks the strongman out, becoming St. Crispian's unlikely hero. Afterward, Hawkes is dispirited, murmuring the Latin phrase for "First, do no harm."
That evening, Emma visits a fortune-telling tent with her artist friend Saffronia March. An older Romani woman reads Emma's palm and delivers a striking prophecy: Emma's "true love" line was broken, charred like a tree struck by lightning, a reference to Maxwell Stuart, the young soldier Emma loved who died years earlier. But the tree did not die. It split into two branches, each leading to a different shape of love. The woman declares both paths inherit the love that survived when Emma's first heart was buried. Shaken, Emma writes out the fortune and resolves not to let it consume her.
The early weeks of May bring both tenderness and crisis. Emma and Pierce navigate courting while living under the same roof, with only Emma's irritating Cousin Archibald providing a veneer of respectable male supervision. Pierce reveals he has lost over seventy percent of his savings due to a banking fraud in New York, and Emma recognizes she has unconsciously tied her own sense of security to his. Meanwhile, Aunt Eugenia, Emma's domineering aunt, assigns her an exhausting schedule of social obligations aimed at securing a marriage for Emma's cousin Arabella Spencer.
At the Halton Ball, Emma endures whispers as London society buzzes about her connection to Islington. She submits an account of Hawkes's boxing victory to the St. Crispian's
Gazette, then panics that she has betrayed his privacy; the editor refuses to let her withdraw it. Emma comforts Victoria Braithwaite, a grieving neighbor, and shares her first kiss with Pierce in his studio, losing her balance on tiptoe and grabbing his arm.
Hawkes disappears for weeks. Emma enters his private room above The Cleopatra pub using a key whose ribbon specifies it may only be given to Islington "And Miss Emma M. Lion." She discovers newspaper clippings about bombings carried out by the Fenians, Irish nationalist militants. When Hawkes returns, he explains he has been visiting the family of a man whose letter Emma once saved, and assures her he is not a revolutionary but a vicar who visits imprisoned men with a Catholic priest friend. A trip to Oxford reveals that Emma's fictitious chaperone, Miss Agnes Dowd, is actually a real scholar studying chemistry and English law. On Primrose Hill, Lord Croixton, a wealthy titled aristocrat with a notorious reputation in London society, accosts Emma and tries to bribe her into facilitating an introduction to Arabella, threatening financial control if she refuses. Emma declines and warns Aunt Eugenia, who appears disturbingly calculating rather than outraged.
On June 4, Emma, Islington, and Hawkes depart for Stonecrop, the Duke's country estate in Derbyshire, where his elder sister Mariana, the Countess of Mirrenthorpe, serves as chaperone. The estate comprises a Palladian mansion and the ruins of its medieval predecessor. Islington declares Emma's visit will be one of "absolute and sustained freedom." Emma discovers Islington plays the cello before dawn each morning, a ritual she and Hawkes listen to from the corridor. She wanders ancient oak woods, collects butterflies, and reads Wordsworth. In the woods, she finds Hawkes asleep beneath a tree; he senses her presence without opening his eyes and tells her, "you slip through time."
Pierce arrives unexpectedly early on June 8, and Emma runs across the lawn in the rain to meet him. They share their first truly private kiss in the woods. Around a hilltop bonfire, Pierce firmly says he does not want children, a response that bruises Emma. In the picture gallery, she discovers a portrait of a young Islington beside a woman who looks strikingly like him. She later finds a gravestone in the woods: Hannah Devereux, who shared Islington's birth year and died when they were twenty. His twin sister's existence, and her death, explain the grief Emma has sensed in him.
A day-long walk to the nearby village of Nettle shatters the pastoral calm. Pierce is recognized by Nance, his sister, whom he has not seen in over twenty years. She leads them to their mother's home, where Pierce's bedridden stepfather, a former parish priest who abused Pierce as a child, lies paralyzed from a stroke. Pierce confronts the helpless old man, his fury erupting as he reveals the beatings and a near-drowning. Emma physically intervenes, throwing her arms around Pierce and talking him out of the room. Hawkes follows Pierce into the fields with boxing gloves, and the two spar until Pierce's anger is spent.
Pierce retreats to London for several days. Islington confronts Emma about her relationship with Pierce, expressing worry rather than disapproval. Emma overhears Mariana challenge Islington about his friendship with Emma, asking which lost person he is trying to replace. Islington insists he is replacing neither his dead twin nor an old friend who became a countess, declaring that Emma "could walk through the door of our friendship and hold down the last corner." When Pierce returns, he apologizes and offers to end the relationship. Emma refuses sharply, telling him he is "so ready for others to throw you away." Pierce explains his refusal to have children stems partly from fear of repeating the abuse he endured.
Islington's youngest sister Maggie and her American husband Jonathan Revel visit for three days. Maggie is charismatic and sharp-tongued, casually cruel to Islington while charming everyone else. Before leaving, she enlists Emma's help switching the labels on Stonecrop's two garden mazes, renaming the easy one "The Gentlemen's Maze" and the challenging one "The Ladies' Maze."
The group returns to London. Emma attends Aunt Eugenia's ball, where she sees the ethereal Lady Eloise Silver, the daughter of the Countess of Ellam and Arabella's chief rival in the Season's marriage market, who seems to recognize Emma's name and gazes at her with quiet resignation. Emma dreams of the lightning-struck tree from the Romani fortune, green leaves breaking from both charred halves at dawn, and wakes with peaceful hope. The volume closes as a red envelope arrives: Emma has been cast in St. Crispian's annual production of
Julius Caesar. She stays up past three exchanging notes through the wall with Pierce, who quotes Shakespeare back to her.