Paul's former girlfriend and a university professor with a deep love for him, struggling with her past involvement in the Camp PLUS murders and living a solitary life while caring for her father.

Paul's chief investigator known for her exceptional investigative skills, dedication to her career, and loyalty to Paul, although her trust in him wavers due to the Camp PLUS murder case.

Margot Green and Doug Billingham, who were killed during their time at Camp PLUS, with their memories central to the other characters' recollections and the mystery of the story.

A former KGB agent and close family friend, supporting Paul with his vast connections and wealth while carrying a past marked by hardship and regret.

Paul's in-laws, with Greta caring for Paul’s daughter out of family loyalty and Bob entangled in an embezzlement scandal that tests Paul’s morals and sense of justice.

Paul’s parents, whose troubled past and the mystery surrounding his sister’s disappearance significantly influence Paul’s life and choices.

A convicted serial murderer known as the Summer Slasher, whose association with the Camp PLUS murders haunts the storyline and challenges Paul’s pursuit of the truth.

Paul's deceased wife, Jane, remembered for her strength and kindness, and their young daughter, Cara, who reflects Paul's qualities and struggles with her mother’s death.

Lucy’s father, a former free-spirited hippie now living in a rehab facility, whose past decisions and current mental state impact Lucy’s life and the Camp PLUS case.

A young girl entangled in a high-profile legal case, seeking justice and financial security, with her testimony central to one of Paul’s significant legal battles.

Gil's family, who obstruct Paul’s quest for the truth to protect their son and the comfortable life they built after the Camp PLUS incident.

Two detectives initially antagonistic toward Paul due to a murder investigation but later allies, with contrasting approaches that affect their interactions with him.

Defense lawyers for a case against a client of Paul’s, with Flair’s strategic intelligence and Mort’s impulsiveness creating obstacles for Paul during the trial.

An undercover private investigator initially working against Paul, using her charm and intelligence to obtain information and later aligning with a different detective.

A wealthy and influential man determined to protect his son, willing to use his resources and connections to challenge Paul’s integrity and threaten his position.

An adept private detective with a vibrant personality, pivotal in assisting Paul’s investigation and uncovering crucial details related to his case.

A teaching assistant and informant who meddles in Lucy’s life, characterized by his perpetual student status and questionable loyalty.