Mark Nelson

Introduces the narrator, a new detective joining Mercer's team. Mark Nelson is a detective who spoke with Eileen earlier in the day. Detective on his first day, arrives late, receives briefing and is dispatched to a suburban homicide scene for door‑to‑door canvassing. Mark takes command of his first assignment, leads the team, conducts door‑to‑door canvassing and is later tasked with reading the case file after the briefing. First day as detective: signs in, gets ID photo, receives a cryptic message, and is sent to canvass the Simpson homicide Mark starts his first day under Mercer, reviews the 50/50 file and handles coffee duties. Narrator reveals personal background, recent breakup, current housing, and thoughts on the 50/50 case Detective present at hospital, interacts with Doctor Li, receives instructions not to interview Scott now, tasked with security and room setup Detective Mark Nelson conducts an interview with Scott Banks in the hospital, attempts to reassure him about Jodie, uses a recorder, and plans to keep him calm while gathering information. Narrator recounts his first day as detective, navigates hospital corridors, uses lift, and coordinates debrief with the team. Conducts the 3 a.m. interview with Scott and relays search orders Mark summarizes Scott’s second interview, prepares an alert message for the comms van, and repeatedly spills hot coffee while fetching it for the team. Mark Nelson is present at 4:10 A.M., receives coffee from Mercer, reads Geoff Hunter’s investigation summary on James Reardon, and notes detailed background information about the case. Nelson activates webcam, prepares report for Hunter, observes White’s orders and contacts Dwyer about the attack Mark conducts the early‑morning interview with Scott, shares his own drowning‑related trauma involving Lise, and urges Scott to help find Jodie before dawn. Conducted interview with Scott, monitored map progress, sent urgent request to comms, uploaded interview, reflected on emotional burden Analyzes the wall photographs at Carl Farmer's house, examines the poem and spider‑web drawings, opens the James Reardon file and anticipates Mercer's arrival. Mark receives radio instructions from John while moving through the woods Mark continues searching files and uncovers new leads about Reardon and the killer’s use of his photograph. Mark raced through the hospital at 6:58 A.M., observed the brutal killing of the security guard, noted the open window and possible escape route for Barnes, called for assistance and ordered the corridor cleared, and received a call from Mercer later in the chapter. Mark was first on scene at Mercer's house, confronted Barnes and rescued baby Karli Appeared at the funeral, spoke with Jodie, handed her his business card, and concealed an envelope for future use.