Joy is a sixty-something retired tennis coach and mother of four adult children. Adjusting to a quiet retirement in Sydney after decades of running a highly respected tennis academy, she feels the weight of unresolved family tensions. She is maternal and generous, quickly taking in a bruised stranger who arrives at her door. This unexpected houseguest coincides with Joy's own sudden disappearance on Valentine's Day.

Stan is a moody and volatile former world-renowned tennis coach who ran an elite academy alongside his wife for decades. He is fiercely competitive, known for his authoritarian discipline over his children, and harbors deep frustrations over the loss of a past star pupil. When Joy goes missing, Stan's history of walking away from conflicts and his scratch-marked face quickly make him the prime suspect.

Savannah is a young woman who shows up unannounced at the Delaney home. She quickly becomes a fixture in the household, doing the cooking and keeping Joy company. Her sudden arrival acts as an instigating force for the family, drawing out old resentments and suspicions among the Delaney siblings as they investigate her background.

Brooke is one of the four Delaney siblings and a former promising tennis player. Her competitive career was derailed by severe stress-induced migraines. She runs a floundering homeopathic physiotherapy clinic and secretly struggles with the recent departure of her husband.

Amy works part-time as a taste tester for a food conglomerate, checking if household dishes are sufficiently salty or sweet. She lives in a shared flat and struggles with various mental health diagnoses, including bipolar disorder and ADHD. Despite her erratic behavior, she is the sibling who attempts most directly to address the family's complex history.

Troy is a wealthy stock investor who uses expensive cars and high-risk trading to mask his underlying restlessness. Like his siblings, he was once a tennis prodigy, but his volatile temper ruined his chances at a professional career. He harbors guilt over a casual airport-lounge affair that ended his marriage.

Logan is a community college teacher specializing in business communications, a subject he pursues with calculated indifference. He maintains a studied emotional distance from life, coasting through his days rather than committing to goals. This passive trait recently drove his live-in girlfriend to pack up and move across the country.

Harry is a highly successful, multiple Grand Slam-winning tennis star. Years ago, he was the prized protégé of the Delaney tennis academy before abruptly leaving for a different coach. His sudden departure deeply fractured the Delaney family and destroyed Stan's chance at global coaching fame.

Indira is Logan's ex-girlfriend. Frustrated by his emotional distance and passivity, she moved across the country. Her absence leaves a profound mark on Logan's daily routine, as he finds himself missing her idiosyncratic habits.

Simon is Amy's socially awkward roommate and casual partner. Recovering from a broken long-term relationship, he provides Amy with sweet, uncomplicated companionship. He uses his computer skills to help investigate the mysteries surrounding the Delaney family.

Claire is Troy's ex-wife, whose marriage ended due to his casual infidelity. She reaches out to him with a sensitive request regarding the embryos they froze during their marriage, prompting him to confront his past selfishness.

Dave is an artist and Savannah's ex-boyfriend. Contrary to Savannah's dramatic tales of an abusive partner, he lives in a neat, upscale apartment. He presents a confusingly harmless, Harry Potter-like demeanor to the Delaney brothers.

Grant is Brooke's husband of six years who recently and unexpectedly left her. His departure is a closely guarded secret that Brooke struggles to hide from her highly critical family during their holiday gatherings.

Steffi is the Delaneys' family dog, named after the famous tennis player Steffi Graf. She keeps Joy and Stan company in their large, quiet house during their retirement years.