The episode begins with a coin sitting on a train track, illuminated by the headlights of an oncoming train. The scene then shifts to a woman's dead body lying on the ground. Elsewhere, forensic pathologist Kay Scarpetta receives a call about the murder. She arrives at the location and discovers that she's been away for a while, as the cops warmly welcome her back. Scarpetta examines the body, whose hands have been cut off at the wrists. Pete Marino, an ex-detective, shows up to remind Scarpetta about Lucy's birthday. They seem very familiar with each other, and she tells him the case is a bad one. She then finds the coin on the tracks and looks at it curiously.
A flashback takes us to 28 years ago in 1998. A young Scarpetta is similarly woken up in the middle of the night by a phone call from Detective Pete Marino. He informs her that there's been a murder. Scarpetta calls a woman she addresses as Yaya to look after the young girl sleeping in the next room – Scarpetta's niece, Lucy. She then goes to the site of the murder, a house where a man named Matt Peterson found his wife, Lori, murdered in their bedroom. Upstairs, we see a very similar body to the one in the present timeline. The wife's body is naked and tied up, and it's also the fourth such murder victim.
At present, Scarpetta is officially sworn in as chief medical examiner once again. She gets a visit from Dr Reddy and Maggie, both figures from her past. Dr Reddy is now a health commissioner and he asks Scarpetta to let Maggie work for her, which Scarpetta doesn't seem too happy about. We then see both versions of Scarpetta conducting an autopsy.
Maggie tells Scarpetta that an Officer Ryan has asked for her. It's unclear what this is about since the next scene shifts to an older Lucy sitting by the grave of a woman named Janet, her wife. In the background is Scarpetta and Dorothy, her older sister and Lucy's mom. They bicker loudly, which annoys Lucy.
In the past, Marino plays an audio recording of his questioning with Matt. He suspects Matt but Scarpetta doesn't believe he's the killer. An FBI agent named Benton Wesley joins in on the investigation. He and Scarpetta think on similar lines about the killer being a sadist.
They soon learn that partial fingerprints belonging to Matt Peterson were found on the deceased body. Scarpetta returns home to find Lucy engrossed in her computer all day. The news about the deceased doctor (Lori) has reached her, and Lucy urges Scarpetta not to follow in her father's footsteps. Scarpetta assures her that she won't.
Upon her arrival, Scarpetta discovers Dorothy impeccably dressed. She's worried about Lucy, who is still grieving Janet on her birthday. Lucy seems to be coping by conversing with an AI version of Janet in the cabin by Scarpetta's house, where she resides. As Scarpetta enters the room, she gifts Lucy a bracelet made of dinosaur bone.
They return to the house, where they are joined by "the husbands" - Agent Benton Wesley and Marino! Benton is married to Scarpetta, while Marino is married to Dorothy. Dorothy suggests that Lucy should return to work and perhaps move out, which frustrates Lucy. Scarpetta pulls Dorothy into the kitchen to tell her to stop, but the argument escalates, and they accuse each other of being detrimental to Lucy. Benton intervenes and tells Scarpetta that she's about to receive a call. It's regarding a missing person who might be one of the Jane Does they found earlier. Scarpetta and Marino head out. She expresses her dislike for Reddy being her boss and tells Marino that she needs him by her side throughout the investigation as she trusts him. She makes him her official forensic operations specialist so he can access crime scenes.
They head to the house of the Jane Doe, Gwen Hainey, a biomedical engineer. Officer Ryan informs them that they have found a weapon that matches her head injury - a kettlebell. He adds that the fingerprints on the kettlebell belong to Matt Peterson. Scarpetta is shocked and tells Marino that they might have got the wrong guy 20 years ago.
The episode ends with a sinister clip of Matt from both past and present.
