Eye of the Abyss is our first-party psychological-horror ARG: psychologist Lin Mo takes a distress letter from a patient watched by another version of himself. 9 acts, 15 puzzles, 24 simulated websites (120 pages), 42 clues, 4 endings, 10–15 hours. Contains psychological horror and sudden audio.
You are a psychologist named Lin Mo. A mysterious patient, Shen Yuan, writes that he is being watched by “another version of himself” — and that this other self is replacing him. You go to the abandoned sanatorium. The letter itself was the trap. 9 acts, 15 puzzles, 24 simulated websites (120 pages), 42 clues, 17 emails, 4 endings, 8 unfiled session recordings, 10–15 hours.
You are Lin Mo, a psychologist. One day a mysterious patient named Shen Yuan sends a distress letter: he says he is being watched by “another version of himself”, and that this other self is gradually replacing him. You decide to visit the abandoned sanatorium where he is staying.
The game states the premise plainly at the start: the letter itself is a trap — the moment you read it, you are already part of the Eye of the Abyss. What really sends you is not professional curiosity: lately you have started hearing, in the dead of night, a sound that should not exist — a hum at 18.98 Hz.
It is played as a pseudo-interface investigation: the game is a browser and you hop between twenty-four simulated websites (the sanatorium, Shen Yuan's blog, the Rust River forum, medical records, acoustic research, frequency archives, surveillance, basement blueprints, patient zero, diaries, timelines, treatment logs and more) — 120 pages in all — advancing by keyword search.
The horror is psychological: surveillance, identity replacement, and the suspicion that every time you “treat” someone you are spreading it. It also uses sudden audio and jump cuts; see the next section.
There is a checkbox you must tick before entering, and the warning is the game's own: it contains horror, thriller and psychological pressure, with sudden sounds, flicker and jump cuts; it advises against play by people with photosensitive epilepsy or lower tolerance, and says to close the page immediately if unwell.
The same screen carries the fiction notice: all people, places, institutions and events are invented — do not read them as real information, and do not imitate them.
This page will not soften that. It is the heaviest psychological entry on the site and a different experience from Unclaimed or Last Online.
The four are decided by the final choice; the hidden and secret endings also require a minimum number of clues, listed in the walkthrough.
With all eight session tapes, every ending gains a page headed “Session Nine.” It changes no branch; it is their shared coda.
Lin Mo recorded eight sessions at the sanatorium; none entered the official files. One unseals per act, each with the patient, date, duration, transcript and the clinical note at the foot of the page.
Shen Yuan appears in four of them; a Xinyuan worker and a night nurse take one each; the remaining two patients are Lin Mo. The photo album in session seven and the silence in session eight are the closest this game comes to the doctor being treated.
The entrance is at the top of the evidence panel: “Unfiled session tapes n/8.” All eight are guaranteed before the final chapter; with the full set, every ending gains a page called “Session Nine”: no patient, Lin Mo on this side of the chair, pressing record.
The tapes give no puzzle answers. They fill in what each side of the therapy chair heard.
The eight object photographs are AI-generated illustrations used to fill in the objects, not screenshots of the game.
It is the largest game here: 10–15 hours, twenty-four sites, 120 pages, 42 clues, 17 emails. The length does not come from puzzle count but from documents that refuse each other.
The subject is rare in web puzzles: it makes the therapeutic relationship itself the horror. The more competent you are, the more you want to help — and the more you spread. Each of the four endings prices that trade differently.
The registers are kept distinct: records are cold timelines, diaries are first-person cracks, the blog is public performance, footage is pure evidence. One event, four versions, is the core loop.
If you want one long game from this site, this and Rust River are two different roads: one inward (identity and surveillance), one outward (pollution and investigation).
Xinyuan Smelting, where Shen Yuan once worked, is the company whose bore broke through in Rust River; the Rust River forum is one of this game's sites too.
The same map also holds coastal Lan City (The Sunken City, Tide Sound Archives). This game owns the hillside sanatorium.
No required order. Playing Rust River first makes one institution name recognisable; playing this first means meeting the same low frequency elsewhere.
Nine acts come from acts.js, fifteen puzzles from puzzles.js, twenty-four sites from locations.js and 120 pages from the summed entries of the pages-*.js files; 42 clues from clues.js, 17 emails from emails.js and four endings from endings.js.
The 10–15 hours is the game's own stated playtime; 18.98 Hz, S.P.S., and the 1953/2003 dates appear in the game text.
The eight sessions, dates, patients, transcripts and clinical notes come from sessions.js; the build gate checks one session per act, all eight images, and runs negative controls.
Both screenshots were taken from the running game on 2026-10-19. The hero image is an AI-generated illustration, not a game screenshot, labelled at the top of the page. If a number here disagrees with the game, the game is right; tell us in the changelog.
For players happy to read a large volume of contradictory documents and to accept psychological horror; also for readers interested in unreliable narration and identity themes.
Not for players wanting something light, nor for anyone unwilling to tolerate sudden audio, flicker and jump cuts; people with photosensitive epilepsy should not play.
Do I need an account or payment?
No. It runs in the browser, free, with no account or in-app purchases.
Is there horror content?
Yes. The game's own warning states horror, thriller and psychological pressure with sudden sounds, flicker and jump cuts; you must tick it to enter.
How long is it?
About 10–15 hours; seeing all four endings takes longer.
Where is progress saved?
Locally in the browser. Refresh or close and continue; it does not sync across devices, and clearing site data restarts.
What if I am stuck?
Check the clue counter and notes at the bottom; whatever is missing points at the site that holds it. Answers are always in unlocked pages.
Can I switch to English?
Yes; the interface and the site content have English versions.
Can I miss the session tapes?
No. They unseal one per act and are complete before the final chapter; the full set adds a “Session Nine” page after every ending.
Is this a true story?
No. It is an entirely fictional interactive game; the people, places, institutions and events are invented and should not be read as real information.
Start investigation — Runs on its own subdomain · progress saved locally · psychological horror with sudden audio