A detective's attraction to Song Seo-rae transforms investigation, concealment, and separation into an irreversible tragedy.
Story Structure — 5 Plot Phases
A Fall Beneath Suspicion
Ki Do-soo's death launches an investigation centered on Song Seo-rae. Physical clues and her restrained grief make her the primary suspect.
Key Events
Mountain Death Discovered — Ki Do-soo is found dead at the foot of a mountain he regularly climbed. Characters: Ki Do-sooLocation: Mountain foot
Widow Interviewed — Song Seo-rae is questioned about Ki Do-soo's death and shows little visible grief. Characters: Song Seo-rae, Ki Do-sooLocation: Police interview room
Suspicious Injuries Found — Investigators note Song Seo-rae's scratch, bruises, broken ribs, and tattoo resembling Ki's initials. Characters: Song Seo-rae, Ki Do-sooLocation: Medical examination area
Nightly Apartment Stakeout — The detective conducts nightly stakeouts outside Song Seo-rae's apartment and becomes fascinated by her. Characters: Song Seo-raeLocation: Outside Song Seo-rae's apartment
The Alibi and the Letters
An apparent alibi and Song Seo-rae's revelations complicate the case. Letters connected to Ki Do-soo support a suicide interpretation.
Key Events
Alibi Confirmed — A client's testimony and CCTV footage place Song Seo-rae at the client's home on the day Ki died. Characters: Song Seo-raeLocation: Client's home
Past Killing Revealed — Song Seo-rae admits that she gave fentanyl pills to her terminally ill mother at her mother's request. Characters: Song Seo-raeLocation: Police interview room
Letters Expose Corruption — Song Seo-rae provides letters in which Ki Do-soo admits corrupt business dealings. Characters: Song Seo-rae, Ki Do-sooLocation: Investigation office
Death Ruled Suicide — The detective interprets a letter as a suicide note and clears Song Seo-rae despite Soo-wan's doubts. Characters: Song Seo-rae, Ki Do-soo, Soo-wanLocation: Police station
Desire Erases Evidence
Song Seo-rae and the detective become emotionally close through dates and private visits. She burns evidence while the investigation quietly remains unresolved.
Key Events
Temple Date — Song Seo-rae and the detective go on a date at a Buddhist temple and grow closer. Characters: Song Seo-raeLocation: Buddhist temple
Evidence Photos Burned — Song Seo-rae burns photographs from Ki Do-soo's case, saying disturbing cases cause the detective's insomnia. Characters: Song Seo-raeLocation: The detective's apartment
Phone Swap Detected — The detective discovers that Song Seo-rae and her client possess identical phone models. Characters: Song Seo-raeLocation: Client's home
Stair Count Revealed — The client's phone records movement equivalent to climbing 138 flights of stairs on Ki's death day. Characters: Song Seo-raeLocation: Client's home
The Hidden Mountain Truth
A phone swap and unusual movement record expose the method behind Ki Do-soo's death. The detective confronts Song Seo-rae but chooses to conceal the evidence.
Key Events
Mountain Method Reconstructed — The detective concludes that Song Seo-rae switched phones, escaped CCTV, climbed the mountain, and pushed Ki. Characters: Song Seo-rae, Ki Do-sooLocation: Investigation office
Apartment Confrontation — The detective accuses Song Seo-rae of forging the suicide note and approaching him to destroy evidence. Characters: Song Seo-raeLocation: Song Seo-rae's apartment
Evidence Sent To Sea — The detective covers up the evidence and instructs Song Seo-rae to throw the incriminating phone into the sea. Characters: Song Seo-raeLocation: Apartment and seaside
Second Husband Found Dead — Thirteen months later, Song Seo-rae's new husband is found dead in a mansion swimming pool. Characters: Song Seo-raeLocation: Mansion swimming pool
Pool Evidence Altered — Song Seo-rae admits only that she drained the pool so the detective would not be disturbed by blood. Characters: Song Seo-raeLocation: Mansion swimming pool
The Tide Keeps Her Secret
A second death and Cheol-seong's confession reopen suspicion around Song Seo-rae. After a final meeting, she disappears beneath the rising tide.
Key Events
Pool Evidence Altered — Song Seo-rae admits only that she drained the pool so the detective would not be disturbed by blood. Characters: Song Seo-raeLocation: Mansion swimming pool
Cheol-seong Confesses — Cheol-seong confesses to the killing, denies Song Seo-rae's involvement, and reveals the phone tracker. Characters: Cheol-seong, Song Seo-raeLocation: Police station
Ashes Scattered Mountain — The detective scatters Song Seo-rae's family ashes, and she reveals that she kept the phone from Ki's case. Characters: Song Seo-raeLocation: Song Seo-rae's grandfather's mountain
Beach Burial — Song Seo-rae buries herself in a sand pit as the tide rises, leaving the detective unable to find her. Characters: Song Seo-raeLocation: Beach
Story Breakdown
Mountain Death — Ki Do-soo's death establishes the mystery and places Song Seo-rae under suspicion.
Body At The Foot — Ki Do-soo is found dead below a mountain he often climbed.
Suspicious Widow — Song Seo-rae's injuries, tattoo, and restrained grief intensify suspicion.
Unstable Alibi — Testimony, CCTV, and Song Seo-rae's past make the first case morally and factually uncertain.
Client Testimony — A client and CCTV appear to place Song Seo-rae elsewhere.
Fentanyl Confession — Song Seo-rae admits giving fatal medication to her mother at her request.
Letters And Desire — Evidence from Ki Do-soo supports a suicide ruling while emotional intimacy grows.
Corrupt Letters — Letters from Ki Do-soo reveal corrupt business dealings and suggest suicide.
Temple Intimacy — Song Seo-rae and the detective date and become increasingly close.
Hidden Phone Trail — A duplicated phone and movement record reveal how Song Seo-rae defeated the apparent alibi.
Switched Devices — Song Seo-rae is inferred to have exchanged phones with her client.
Mountain Reconstruction — The detective concludes that Song Seo-rae climbed the mountain and pushed Ki Do-soo.
Compromised Justice — The detective recognizes the truth but chooses emotional loyalty over professional integrity.
Apartment Accusation — He accuses Song Seo-rae of manipulating him and destroying evidence.
Phone In The Sea — He instructs her to dispose of the incriminating phone and conceals the evidence.
Second Death — A later killing reopens the relationship between suspicion, manipulation, and concealed responsibility.
Pool Discovery — Song Seo-rae's new husband is found dead in a mansion swimming pool.
Cheol-seong Confession — Cheol-seong claims responsibility and denies that Song Seo-rae participated.
Final Vanishing — The remaining evidence and a last meeting lead to Song Seo-rae's deliberate disappearance.
Ashes At The Mountain — The detective scatters family ashes and Song Seo-rae reveals that she kept the phone.
Buried By The Tide — Song Seo-rae enters a sand pit and lets the rising tide conceal her.
From a mountain peak in South Korea, a man plummets to his death. Did he jump, or was he pushed? When detective Hae-joon arrives on the scene, he begins to suspect the dead man’s wife Seo-rae. But as he digs deeper into the investigation, he finds himself trapped in a web of deception and desire.
