The third installment of "Happy Face" kicks off with Melissa's video gaining viral status, its impact rippling through cyberspace. Hazel updates her, noting that the overwhelming majority of responses are positive. Meanwhile, the enigmatic blond man from the preceding episode catches wind of Melissa's video. We witness him hastily packing his camper van and setting off on an undisclosed journey.
Melissa crosses paths with Ivy, who fills her in on the ongoing protests demanding Elijah's release. Greg then enters the scene, propositioning Melissa to serve as a consultant producer for their show's coverage of the case. He extends an invitation to Melissa and Ben for dinner at his residence that very evening. In trust, Melissa entrusts Ivy with the unopened letters from Keith, hoping they might contain further insights.
Upon arriving at Greg and Roxanne's home for dinner, Melissa is taken aback to discover that Greg has flown in his manager, literary agent, and a film producer, creating an air of anticipation. Back at her place, Hazel unlocks Melissa's safe, retrieving the drawings Keith once sent. She subsequently logs onto a website where Keith's artwork is being auctioned by others.
The blond man unexpectedly shows up at Melissa's doorstep. A memory flashback reveals the court proceedings where Keith was convicted for the murder of Louise Nelson. Louise's son, Ashton, delivers an emotional statement about his mother's demise, while Keith mocks from the dock. Presently, a grown-up Ashton knocks on Melissa's front door, which her son innocently opens.
At Greg's dinner gathering, his literary agent broaches the idea of Melissa penning a book. The conversation shifts gears, delving into the tragic incident where Keith slaughtered the cats Melissa once cherished. The discourse on her parents becomes overwhelming, prompting Melissa to excuse herself for a restroom break. As she departs, a server confides in Melissa that her brother had taken a life, to which she offers heartfelt comfort.
Inside the prison walls, Keith and his fellow inmates are granted permission to witness Melissa's segment on Greg's television show. Keith's fury escalates as he dials Melissa's number, lambasting her for turning the program into a narcissistic spectacle. He further accuses her of obtaining inside information from a guard, hinting darkly at her inherited psychopathy, much like her father's. Melissa, left baffled, leaves a voice message at the Oregon prison facility, touching upon the sensitive subject of her father and Keith's accusation. Greg, sensing her distress, locates her promptly and inquiries about her wellbeing, urging her to reconsider the proposed deal.
Elsewhere, Ivy and her assistant uncover a letter penned by Barbara, who claims her brother possesses crucial evidence pertaining to the crime. They promptly contact the man, Harold, who reveals he ran an art program within the prison but had no direct interaction with Keith; instead, his engagement was with Elijah. He mentions an incriminating song composed by Elijah and offers to share it with Ivy.
Returning home, Melissa and Ben are astounded to find Max in the company of Ashton and his dog, Buddha. Melissa, enraged, commands Max to retreat indoors and alert the authorities. Ashton, incensed by Melissa's inclusion of his mother's photograph among Keith's victims on television, erupts into a tirade. Ben, sensing the escalating tension, dials 911 while Ashton storms out, leaving an eerie smiley face etched on the glass door as a parting shot.
Ivy and her assistant listen intently to Elijah's song, which appears to confess to Heather's murder. Recognizing its gravity, Ivy speed-dials Melissa, informing her of their impending 6 AM flight to Texas. Thanks to Greg's influential pull, they are granted an audience with Elijah behind bars. When Melissa broaches the subject of the song, Elijah abruptly exits the conversation, clamming up completely. Later, they decipher that Elijah had implied it was Heather who authored the haunting tune, prompting Ivy to insist that they delve deeper into Heather's background.
At school, Hazel finds herself invited by Eva to share lunchtime companionship with her circle of friends. They warmly encourage her to post Keith's intricate drawing online and generously offer Josh's PayPal account to facilitate the potential sale. Before long, the drawing catches someone's eye and finds a new owner.
Meanwhile, within the prison walls, guards conduct a rigorous search of Keith's cell, ultimately uncovering a hidden cellphone. To his astonishment, he learns that it was Melissa who blew the whistle on his illicit possession. Later, Ivy and Melissa meet with Denise, Heather's mother, where Melissa expresses her remorse for the pain she has caused. Denise shares a heart-wrenching tale of how Heather's behavior drastically changed after she started dating Elijah—smoking, staying out late, and bearing mysterious bruises on her arms.
Ben then reaches out to Melissa, urging her to seek a restraining order against Ashton. Melissa, however, resists, prompting an outbreak of frustration from Ben and leading to a heated exchange. Ivy notices Melissa's distress and gently probes, prompting a confession. Melissa reveals her fear of re-traumatizing those she cares about. Ivy, drawing from her father's wisdom as a reporter, reminds her that the truth, like light, has the power to heal.
Their conversation is interrupted by a visit from the District Attorney. He reveals that another DA has contacted him, disclosing that Keith has confessed to another murder. However, upon closer inspection, it becomes evident that this confession is a sham, orchestrated by the actual perpetrator who paid Keith to take the fall. To revisit Elijah's case, the DA emphasizes the need for irrefutable physical evidence.
Back in prison, a guard surreptitiously slides Keith a new cellphone. With urgency, he dials a number and conveys his desperate need for a replacement device, undeterred by his recent setback.
Ivy and Melissa proceed to converse with Heather's friend, who unveils that Heather had once recorded a demo of her music with a producer who was closely acquainted with Elijah. They subsequently encounter Elijah, who discloses that the producer's name was Lucius, but unfortunately, he has now departed from this world. Elijah extends his apologies for his earlier outburst.
Elijah then elaborates that he copied Heather's song for his prison art session out of frustration with the teacher's persistent presumption of his guilt. He further recounts his final evening with Heather, revealing that they had a casual encounter but were not in an exclusive relationship.
As they make their way back, Melissa stumbles upon an internet article detailing her abortion at the tender age of fifteen. The revelation strikes her hard, prompting her to instruct Ivy to halt the car abruptly. Melissa instantly suspects her ex-boyfriend, Brandon, of leaking the information to the press. Just then, Ivy catches sight of a church adorned with a sign that mirrors one she had previously seen on one of Keith's letters to Melissa.
Curiosity piqued, they step inside and engage with the pastor, who recognizes Keith. The pastor reveals that Keith had visited the church and requested his prayers. Moreover, he mentions that Keith was accompanied by a young boy, whom Melissa recognizes as Shane, her brother, from the closing scenes of Happy Face Episode 3.
