Augusta is a fiercely independent and intelligent pharmacist who recently moved to a retirement community in Rallentando Springs, Florida. She dedicates her life to western medicine to honor her father's legacy. She maintains a guarded exterior that masks her tenderhearted nature. In her youth in 1920s Brooklyn, she balances her father's scientific rigor with a fascination for her great-aunt's herbal healing. She harbors a deep, lingering hurt from a romantic betrayal she experienced as a teenager.

Irving is an energetic retiree living in Florida who reconnects with his teenage love after more than six decades apart. He grows up impoverished in Brooklyn, originally working as a delivery boy for the Stern family pharmacy. Though he lacks formal education in his youth, he possesses immense emotional intelligence and a protective nature toward those he cares about. In his later years, he takes college literature courses and swims daily, maintaining a mischievous charm.

Esther is a Russian-born traditional healer who brings her old-world remedies and authoritative presence into the Sterns' Brooklyn apartment. She wears a dark babushka and utilizes an inscribed mortar and pestle. She dispenses herbal treatments and chicken soup to the local neighborhood. She acts as a mentor to Augusta, teaching her about intuition and the emotional aspects of healing.

Solomon is an established pharmacist and devoted father who raises Augusta and Bess after his wife's passing. He relies strictly on western medicine and empirical evidence, dismissing alternative treatments as mere superstition. He operates his business with compassion but worries deeply about his professional reputation, especially when local bootleggers pressure pharmacists during Prohibition.

Mitzi is the glamorous and calculating wife of a notorious local bootlegger. She wields considerable influence within her Brooklyn community, approaching the criminal underworld with an icy, strategic mindset. She fiercely protects her family's interests and power, using intimidation and manipulation to bend others to her will.

Zip is a powerful organized crime figure and racketeer operating in Brooklyn during Prohibition. He intimidates local business owners, including pharmacists, to support his illegal liquor operations. Despite his fearsome reputation in the criminal underworld, he displays protective instincts toward his family members.

Bess is Augusta's older sister and lifelong confidant. She works in the family store during her teenage years and frequently catches the attention of the young man running the soda fountain. She provides a romantic parallel to Augusta, experiencing courtship with a serene, patient demeanor.

George is a reliable employee at the Stern pharmacy who harbors clear affection for Bess. He acts generously toward the younger staff, frequently ensuring the impoverished Irving gets enough to eat during his shifts.

Jackie is Bess's daughter and Augusta's closest living relative in the present-day timeline. She maintains a strong bond with her aunt, visiting her in Florida and bringing crucial family heirlooms that force Augusta to confront her past. She actively encourages Augusta to embrace life and pursue romantic happiness.

Nathaniel is a childhood friend from Brooklyn who now lives in the same Florida community as Augusta and Irving. In his youth, his impulsive behavior at a restaurant inadvertently causes a massive rift between Augusta and Irving. As a widower in the present day, he seeks companionship and attempts to work through a lingering, unspoken tension with Irving.

Evie is a youthful friend of Augusta in 1920s Brooklyn. She becomes the center of attention during a major celebratory dinner when Nathaniel makes a grand romantic gesture toward her.

Lois is the daughter of prominent Brooklyn bootleggers. She moves in sophisticated social circles and frequently interacts with the local youth, acting with a level of privilege that contrasts sharply with Irving's working-class background.

Irene is Augusta and Bess's mother, whose early death from diabetes fundamentally alters the Stern household. Her absence drives her husband to bury himself in work and instills in Augusta a deep awareness of western medicine's limitations.

Shirley is a friendly, outgoing resident at the Florida retirement community who quickly befriends Augusta. She acts as a sounding board for Augusta's romantic confusion and keeps close tabs on the social dynamics among the retirees.

Harold is a Rallentando Springs resident who plays tennis with Irving and participates in local social events. He helps share information among the community members and inadvertently sets certain reunions in motion.

Vera is a resident of the retirement community who actively pursues a romantic relationship with Irving. She acts aggressively territorial regarding his attention and confronts Augusta when she feels threatened.

Freddie is a Brooklyn neighborhood bully who torments younger children and engages in petty theft. His aggressive actions draw the ire of both Irving and the local organized crime figures.

Sammy is the young son of Zip and Mitzi Diamond. When Irving intervenes to protect him from neighborhood thugs, the event sparks a complicated connection between Irving and the powerful Diamond family.

Harriet is the distressed wife of a traveling shoe salesman who seeks help from the Stern pharmacy. After Solomon refuses her dangerous request, she turns to Esther's traditional remedies for assistance.

Fanny is a customer who visits Esther to request a love elixir. She uses the traditional remedy to gain clarity about her husband's infidelity and make a definitive choice about her future.