Christopher decodes Master Benedict's gunpowder cipher and fires a makeshift cannon in the apothecary shop, causing significant damage.

Master Benedict returns to find the shop damaged and learns Christopher cracked the cipher, then assigns him a Latin punishment.

Rival apothecary Nathaniel Stubb arrives at the shop and informs Master Benedict that another person connected to apothecaries has been murdered.

Christopher eavesdrops from the pigeon coop as Stubb pressures Master Benedict to choose a side regarding the ongoing murders.

Master Benedict returns home late at night badly burned and injured, and Christopher treats his wounds.

Master Benedict gives Christopher a mysterious antimony puzzle cube as both a personal gift and a hidden challenge.

Master Benedict strikes Christopher in front of customers and sends him on a false errand to purchase natron.

Christopher returns from the errand to find Master Benedict has been murdered and bound inside the closed shop.

Lord Ashcombe questions Christopher about the murder, and Christopher secretly removes a coded page from the shop ledger.

Christopher and Tom decode Master Benedict's hidden ledger message, which points them toward a location connected to Hugh.

Three apprentices working for Oswyn lock Christopher inside an office at the Guild Hall and attempt to kill him.

Isaac the bookseller reveals that Master Benedict was one of seven alchemists who secretly sought the dangerous Prima Materia.

Christopher lures Oswyn to the mausoleum garden, where Lord Ashcombe appears to arrest him and Oswyn confesses to ordering the murders.

Christopher pulls Lord Ashcombe into an empty oven just before the underground workshop explodes, killing Oswyn and his men.

Isaac presents Master Benedict's authenticated will to the Guild Council, and Christopher is confirmed as the shop's legal heir.

Christopher begins as a clever but reckless apprentice who decodes a gunpowder cipher for fun, unaware that a cult is murdering London's apothecaries. When Master Benedict is killed, Christopher becomes both a prime suspect and a detective, secretly holding onto a coded ledger page his master left behind. He decodes the message and follows the clues while facing danger from the Guild, the law, and the killers themselves. The trail leads him to discover the terrifying secret of the Archangel's Fire hidden beneath a city mausoleum. Christopher sets a trap for the true murderer, Guild Council member Oswyn, luring him into an underground workshop that explodes during the confrontation. In the aftermath, Christopher is cleared of all suspicion and confirmed as the rightful heir to Master Benedict's apothecary shop.

The headline events of Christopher's quest to solve his master's murder.

Tom brings Christopher a birthday apple pie, and the boys solve the puzzle cube by pouring quicksilver into the keyhole.

During the Oak Apple Day holiday, Christopher throws rotten eggs at Stubb after a girl knocks off his oak sprig.

Lord Ashcombe and his soldiers dig a human arm out of the ground in a private garden on Oak Apple Day.

After returning to find boar's blood splattered across the shop, Master Benedict rushes out without his apothecary's sash.

After the murder, Stubb claims rights to the apothecary shop and the Guild Council prevents Christopher from retrieving his belongings.

Christopher moves into the Bailey family's bakery after being displaced from the apothecary shop by the Guild and Stubb.

Christopher and Tom visit Hugh's physician employer but are told Hugh has not been seen in several days.

Christopher and Tom break into the ransacked apothecary shop at night, and Christopher retrieves Master Benedict's sash and the puzzle cube.

Hiding under a table in the dark shop, Christopher overhears Stubb and Wat confirm that Master Benedict took madapple to avoid torture.

Christopher uses gunpowder made from sash ingredients to ignite the fireplace, creating a diversion that lets him and Tom escape.

Tom tells Christopher that the arm Lord Ashcombe dug up on Oak Apple Day was Hugh's, who died in an accident.

Christopher disguises himself with squid ink and visits Isaac's bookshop under a false name before confessing his true identity.

Christopher and Tom pour the correct combination of chemicals into the mural wall holes, opening the hidden inner workshop door.

Tom accidentally knocks over a beaker of Archangel's Fire in the testing room, triggering an explosion that injures both boys.

Tom arrives in the ruined workshop and strikes Wat over the head with a rolling pin, saving Christopher from harm.

While the main investigation unfolds, Christopher's world is shaped by a series of significant events that test his resourcefulness and reveal crucial truths. A birthday celebration turns into a puzzle-solving breakthrough, a holiday outing ends with the discovery of a buried body, and the murder forces Christopher out of his home and into the Bailey family's care. Breaking into the ransacked shop at night, Christopher overhears a confession about his master's death and narrowly escapes using the ingredients in Master Benedict's sash. As the investigation deepens, a disguised visit to a bookseller leads to a secret underground library, and a return to the hidden workshop ends in an accidental explosion. The resolution finally comes when Tom, armed with nothing but a rolling pin, delivers the blow that stops the last surviving villain from harming Christopher.

The supporting moments and discoveries that shaped Christopher's investigation.

Injured Master Benedict asks Christopher if he would rather leave his apprenticeship, and Christopher firmly refuses to go.

Alone at the Bailey bakery, Christopher realizes Master Benedict's public cruelty and false errand were designed to save his life.

Christopher vows to decode Master Benedict's hidden message and find the true murderer responsible for his master's death.

Visiting the Guild Hall, Christopher learns from Oswyn that the Cult of the Archangel is real and desires the Fire.

Oswyn reveals that Master Benedict's will has disappeared from the Guild vault, leaving Christopher's future at the shop uncertain.

Following Master Benedict's coded clues, Christopher and Tom discover a crumbling mausoleum serving as the entrance to a hidden crypt.

Christopher finds a charred testing room and an unidentified oily yellow liquid inside Master Benedict's secret underground workshop.

Trapped in the Guild Hall office, Christopher realizes the apprentices who guided him there are Oswyn's agents sent to kill him.

Christopher drips oil of vitriol from the apothecary sash onto the office door lock, dissolving it and breaking free.

Tom's sisters lead Christopher to shelter in Dr. Parrett's fire-damaged house after the Bailey family is forced to turn him away.

Christopher realizes that his earlier suggestion about using sawdust was what allowed Master Benedict to successfully stabilize the Archangel's Fire.

Rather than flee the city, Christopher prepares a cylinder of Archangel's Fire and sends two timed letters to spring a trap.

Oswyn reveals that a spy informed him of Christopher's letter to Lord Ashcombe before Oswyn even received his own invitation.

Wat strikes Lord Ashcombe with an ax, and Oswyn burns Christopher with oil of vitriol to force the Fire's location from him.

Christopher secretly conceals the Archangel's Fire recipe inside the ice vault, refusing to surrender it to Lord Ashcombe or any institution.

At every stage of the story, Christopher faces choices and discoveries that fundamentally change the direction of his quest. It begins with his refusal to abandon his master and ends with his decision to hide a dangerous secret from even those who helped him. Between these two moments, Christopher pieces together the truth about his master's false cruelty, the existence of the Cult, and the real identity of the murderer hiding within the Guild. Each revelation carries weight, from learning that sawdust could stabilize the Archangel's Fire to understanding that the apprentices at the Guild Hall were sent to kill him. The final confrontation forces Christopher to endure torture and watch his ally fall before his trap is sprung. These turning points reveal not just the plot's secrets but the growth of Christopher from an impulsive boy into a capable and responsible young apothecary.

The key decisions and revelations that turned the tide of Christopher's adventure.