The short answer for what to do with the Artificial Eye is this: you use it to unlock the Grandfather Clock in the Alchemist's Study, revealing a hidden passage to the Marionette's Workshop. This is a mandatory step to reach the game's final boss and complete the main story. However, this seemingly simple key item also has a secret secondary function tied to achieving the game's elusive "True Strings" ending.
This guide breaks down every step, from acquiring the eye to its dual purposes, ensuring you miss none of the grim secrets hidden within The Puppet's Casket.
First, How Do You Get the Artificial Eye?
You can't use the eye if you haven't found it. The Artificial Eye is a guaranteed drop from the mini-boss known as the Gilded Watcher, located at the pinnacle of the Observatory Tower. Reaching it is a multi-stage process that serves as the climax of the game's second act.
1. Ascend the Observatory Tower
The Observatory is the large, crooked tower dominating the skyline in the Scholar's Ward. Access is initially blocked by a sealed astral gate. To open it, you must first retrieve the Star-Chart Key from the Grand Library's lower archives, guarded by the Librarian Specter. Once the gate is open, the tower is a straightforward but treacherous vertical climb, filled with clockwork sentinels and maddened phantoms of ancient astronomers.
2. Defeat the Gilded Watcher
At the very top of the Observatory, you'll find a massive orrery. Activating the central console will summon the Gilded Watcher. This boss is an automaton in the shape of a giant brass owl, and its attacks are based on predictable, timed patterns.
- Phase 1 (100% - 50% Health): The Watcher will use sweeping laser attacks from its eyes. The key is to stay mobile and dodge through the beams just as they fire. It is vulnerable for a few seconds after completing a three-sweep combo.
- Phase 2 (<50% Health): The Watcher will shatter the glass dome of the observatory, causing shards to rain down periodically. It also adds a shockwave stomp to its arsenal if you stay too close. Focus on ranged attacks if possible, and only move in for melee strikes after it stomps.
Upon its defeat, the Gilded Watcher will crumble, leaving the Artificial Eye gleaming in the wreckage. Pick it up; it will appear in the "Key Items" section of your inventory.
Unlocking the Path: The Grandfather Clock Puzzle
With the eye in your possession, your next destination is the Alchemist's Study. This area is located in the Manor of Chimes, the same sprawling mansion where you began the game, but was previously inaccessible.
Finding the Alchemist's Study
Return to the Manor's main foyer. The large, ornate door on the second-floor landing, previously locked with a "seal of knowledge," will now react to the presence of the Artificial Eye. The seal will dissipate, granting you entry. The study is a circular room filled with bubbling alembics, half-finished homunculi in jars, and a pervasive sense of failure.
At the far end of the room stands a tall, dark-wood Grandfather Clock. As you approach, you'll notice one of its decorative carved eyes is missing—a perfect, hollow socket.
Solving the Clock's Riddle
Simply inserting the eye isn't enough. The clock is a lock, and its combination is a specific time. Interacting with the clock face allows you to move the hour and minute hands.
- Examine the Room: On the main alchemy workbench, you'll find a burned diary. Most of it is illegible, but the final entry is scrawled with panicked haste: "The master is gone. The workshop is sealed. He always said the final door opens only in The Silent Hour."
- Find the Time: The "Silent Hour" is a clue you may have encountered before. In the Grand Library, a lore book titled On the Nature of Time and Silence states that 3:00 AM is traditionally known as the hour of profound silence, when the veil between worlds is thinnest.
- Set the Clock: Interact with the clock face and move the hands to 3:00. The small hand should point directly at the III, and the large hand at the XII.
- Insert the Eye: With the time set correctly, interact with the empty eye socket. A prompt will appear to "Insert the Artificial Eye." Do so.
If the time is correct, the eye will flash with an inner light, the clock will emit a deep chime, and the entire unit will grind backward, revealing a dark, spiraling staircase leading down into the earth. This is the only path to the Marionette's Workshop.
The revealed hidden staircase behind the Grandfather Clock in The Puppet's Casket.
Beyond the Clock: The Marionette's Workshop
The Marionette's Workshop is the final major area in The Puppet's Casket. It is a nightmarish labyrinth of discarded puppet parts, half-sentient marionettes that shamble in the dark, and the final, tragic story revelations of the Puppet Master's work. It is here you will face the game's final boss and determine the fate of the cursed manor.
This area contains:
- The Stringless Horrors: The primary enemies. These are failed puppet experiments, far more aggressive and unpredictable than the clockwork soldiers above.
- The Puppet Master's Diary: A series of five diary entries that piece together the full story of the game's tragedy.
- The Final Forge: A workbench where you can perform one final upgrade on your primary weapon before the final confrontation.
The entire purpose of finding and using the Artificial Eye is to grant you access to this climactic zone. Without it, the story cannot be completed.
The Secret Use: How the Eye Unlocks the "True Strings" Ending
This is where most players stop. However, the Artificial Eye has a second, hidden purpose. Using it in a different way at the very end of the game is the key to the "True Strings" secret ending.
To achieve this ending, you must NOT use the Artificial Eye on the Grandfather Clock. This sounds counter-intuitive, but there is another way forward.
An Alternate Path
Instead of using the eye on the clock, you must first find three Puppet Masks hidden throughout the manor. Wearing all three allows you to pass through the large, ghostly mirror in the Queen's Ballroom, which also leads to a back entrance of the Marionette's Workshop. This is a much harder route, involving a series of difficult platforming challenges and a fight with the Mad Jester.
The Final Choice
If you reach the final boss, the Heart of the Manor, without having used the Artificial Eye on the clock, you will be presented with a different final interaction. After you defeat the boss, you will approach the final, inert puppet at the center of the room. Instead of simply ending the game, you will have a new prompt: "Insert the Artificial Eye into the Puppet."
Doing this triggers the "True Strings" ending, where you embed the eye's observational power into the master puppet, taking control of the Manor's strings yourself instead of simply breaking the curse. This is considered the game's secret, morally ambiguous "true" ending.
Infographic comparing the steps for the standard ending and what to do with the artificial eye for the secret ending.
FAQ: Your Questions Answered
Can you miss the Artificial Eye?
No. The Artificial Eye is a guaranteed drop from the Gilded Watcher, which is a mandatory mini-boss required to progress the main story. You cannot finish the game without fighting it and acquiring the item.
What happens if I try to use the Artificial Eye somewhere else?
Nothing. The item can only be used on the Grandfather Clock's eye socket or, in the specific circumstances for the secret ending, on the final puppet. It has no other function and will not trigger any other interactions in the game world.
Is the "True Strings" ending better?
"Better" is subjective. The standard ending, achieved by using the eye on the clock, provides a sense of closure and release for the spirits in the manor. The "True Strings" ending is darker and more of a power fantasy, suggesting the cycle of control continues with you as the new master. It contains more lore but is morally gray.
I set the clock to 3:00 but it didn't work. What's wrong?
Make sure you are setting it to 3:00 AM, not 3:00 PM. The small hand must be on the III and the large hand on the XII. Some players mistakenly point the large hand to the III as well. The time must be set before you insert the eye.
The Final Takeaway
The Artificial Eye is the lynchpin of the game's final act. Its primary, and most obvious, function is to act as the key to the Grandfather Clock, your gateway to the finale. But its true significance is revealed only to those who dig deeper, rewarding the most observant players with a hidden narrative path that re-contextualizes the entire story. Whether you choose to break the curse or seize the strings for yourself, it all begins with this single, unblinking eye.