Osta Detective Sherlock: Shadow Stalker PC

Featured globally on Google Play, the game ranked No. 4 worldwide and No. 1 in China on the “Popular Upcoming” chart during Steam Detective Fest in January 2026. The full story progression and ending of the EA version are now complete, with full voice-over and subtitles.

EA Version Complete Walkthrough: 

<Game Introduction>

    “When you gaze into the truth, the truth gazes back.”

    This is an immersive mystery deduction game powered at its core by AI large language models.

    You play as Sherlock Holmes, entering the Victorian town of Dartmoor in the 19th century. There, you will match wits with dozens of AI-driven characters and uncover the truth behind curses, lies, and murder.

    There are no fixed dialogue choices. There is no single standard answer.

    You can freely talk to every character: chat, interrogate, test, deceive, comfort, threaten, bribe, praise, or even deliberately mislead them. Every NPC has their own personality, secrets, memories, emotions, and stance. They remember what you say, change their trust in you based on your attitude, and may crack under pressure, slip up, lie, question you back, or even completely break down.

    You are not clicking through dialogue options.

    You are engaging in psychological warfare with NPCs that feel alive. Find clues, expose lies, and break open the secrets hidden in their hearts.

<Storyline>

    In the outskirts of 19th-century London, thick fog surrounds the mysterious Baskerville Hall.

    Sir Charles Baskerville is found dead near the moor. His eyes are wide open, his right hand clutching his chest, yet there are no obvious wounds on his body. Around the scene are traces that appear to belong to a large hound.

    The legend of the demonic hound once again haunts the estate. The new heir, Sir Henry, is consumed by fear. The butler refuses to speak. The doctor is evasive. The inspector is eager to close the case. Everyone seems to know something, and everyone seems to be hiding something.

    “It must be the curse… the Baskerville family curse! The demon hound has returned!”

    “Am I truly unable to escape this curse? No… I don’t want to die… Ah—!”

    Inside the manor, shadows gather. Beyond it, danger waits in the fog. Fear grips every throat like the hand of a demon.

    After Holmes is invited to Baskerville Hall by his friend Mortimer, more deaths follow: a mutilated corpse in the moor, a woman’s body found in the fountain of a neighboring estate…

    Are these seemingly unrelated cases connected? What secret lies behind the Baskerville curse?

    Someone fears the truth.
    Someone is using the legend.
    Someone is hiding a secret.
    Someone is watching from the shadows.

    “Sherlock, you once said every brick of Baskerville Hall whispers… but some secrets are too heavy for even the Thames to swallow.”

    “Then we need sharper ears — perhaps those of a doctor who insists on carving Christmas pudding with a scalpel.”

    When you have eliminated the impossible, whatever remains, however improbable, must be the truth.

<Features>

====== Free Chat！ Become a Real Detective ======

    There are no dialogue options.

    You can freely talk to NPCs in any way you choose: chat, interrogate, deceive, praise, threaten, bribe — anything you can think of.

    NPCs are no longer lines of code, but “living” characters infused with AI: forcing themselves to stay calm under interrogation, scrambling to cover up a lie, gossiping about others, shifting blame, and hiding their true intentions.

    AI makes every character feel alive. You never know whether they will help you solve the case — or stab you in the back.

====== Break Their Mental Locks and Uncover Their Secrets ======

    Everyone has a secret they are trying to protect.

    Some fear exposure.
    Some want to protect loved ones.
    Some do not trust you.
    Some would rather lie than reveal the truth.

    Use conversation, evidence, gifts, items, and emotional pressure to gradually break through their defenses.

Behind every mental lock may lie a crucial clue. Clues connect layer by layer, leading you closer to the final truth.

    A true detective does not simply ask questions.

    A true detective makes people reveal what they never meant to say.

====== Hundreds of Items: Evidence or Gift - Your Choice ======

    Show your evidence and leave the culprit no room to deny the truth.

    Hundreds of items can be found throughout the game. Use them as evidence, or give them as gifts — the choice is yours.

    Give a scalpel to a doctor, and he may praise you as a kindred spirit. Give the same scalpel to a lady, and she might slap you for “cursing” her.

    Each character will react in real time based on their own personality and the current situation — blushing, anger, cold laughter, or even pulling a gun.

    Flirt or provoke. The risk is yours.

====== AI-Driven Twists！Multiple Hidden Endings ======

    “You think catching the killer is the end? The true culprit is laughing at your innocence.”

    Accuse the wrong person, and tomorrow’s newspaper may read: “Sherlock Holmes Disgraced in Framing Scandal.”

    Hide a key piece of evidence, and ten years later, you may glimpse the smile of a supposedly dead baron on a dark street.

    AI will shape the story based on your words, completed tasks, collected clues, and items used, leading to different endings.

— Hush. Did you hear the hound howling deep in the moor?