Among the many mysterious relics scattered across Hollow Knight: Silksong, few are as intriguing or as vital to Hornet’s journey as the Architect’s Key. More than just a collectible, this rotary key unlocks a hidden chapel within the Underworks, granting access to the coveted Architect’s Crest—an item that can reshape the rhythm of combat and progression.

This guide takes you step by step through how to obtain the Architect’s Key, where to use it, and why it holds such importance in Silksong.

Table of Contents:

What Is the Architect’s Key in Silksong?

The Architect’s Key is a Key Item in Silksong, belonging to the ancient lineage of the Architects. Unlike consumables or one-time resources, Key Items open pathways, both literal and narrative, allowing Hornet to venture into otherwise inaccessible areas.

Specifically, this key grants entry into the Chapel of the Architect within the Underworks. Inside, Hornet can acquire the Architect’s Crest, a crest that significantly influences her abilities and combat style during the mid-game.

How to Get the Architect’s Key in Silksong?

Acquiring the Architect’s Key isn’t as simple as stumbling across it—it requires exploration, persistence, and a few prerequisites.

A map of the Underworks in Hollow Knight: Silksong showing Hornet's current location near "Wisp Thicket." The map outlines interconnected areas like "Choral Chambers" and "Whiteward," guiding players to the eastern section. — Credit: Team Cherry

Reach the Underworks in Act 2
- Progress through the Coral Chambers and make your way toward the eastern section of the Underworks.
- This path becomes accessible after obtaining the White Key in the Songclave of the Citadel, which unlocks the elevator into Whiteward.
Find the Twelfth Architect
- The Twelfth Architect NPC can be found above The Cauldron, a landmark within the Underworks.
- He acts as both a vendor and a gatekeeper, offering a range of Tools alongside the coveted key.
Meet the Purchase Requirements
- The Architect’s Key costs 110 Rosaries.
- However, there’s a catch: you must own a certain number of Tools before the Architect will part with the key. If you’ve been skipping tool upgrades, you may need to revisit earlier vendors and expand your inventory first.

Hornet stands before the Twelfth Architect NPC, a large, bug-like vendor, in the Underworks of Hollow Knight: Silksong. A purchase screen is displayed, showing the Architect's Key available for 110 Rosaries, along with a note about a tool requirement. — Credit: Team Cherry

Tip: Many players mistake the requirement as needing to buy all of the Twelfth Architect’s wares. In reality, the condition counts your total number of tools across the game. If you are locked out, hunt down missing tools in other regions.

A professional-looking game review thumbnail for Hollow Knight: Silksong. The central image is a large, stylized render of Hornet with a sleek, modern design. The title "GAME REVIEW" is displayed prominently in a pixelated font, set against a blue background with digital design elements.

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Where to Use the Architect’s Key?

Once purchased, the Architect’s Key unlocks the Chapel of the Architect, located not far from where you first meet the Twelfth Architect.

A screenshot showing Hornet standing in front of a locked gate in Hollow Knight: Silksong. The gate is adorned with an Architect's sigil, and a prompt asks, "Use Architect's Key?" with the options "Yes" or "No." — Credit: Team Cherry

Travel a short distance upward and left from his platform.
Pull a sequence of levers that eventually leads to a locked gate marked with an Architect’s sigil.
Use the key to open the chapel.

Inside, Hornet finds the Architect’s Crest—a crucial mid-game reward. Unlike other chapels in Silksong, this one is eerily quiet, housing no boss or swarm of enemies. Instead, the Crest lies in wait, ready to be claimed.

Hornet stands on a metal platform, looking at the large, ornate diving bell in the fiery Deep Docks area of Hollow Knight: Silksong.

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The Signifinace of The Architect’s Crest

The Architect’s Crest is one of the most sought-after crests in Silksong, offering a unique balance of slots and abilities:

Slots: 3 Red, 2 Blue, 2 Yellow, 0 White
Functionality: Grants Hornet the ability to craft new Tools by spending Silk, adding depth to both combat and exploration.
Combat Flavor: Normal and charged attacks adopt a screw-like pattern, shredding through enemies with mechanical precision.

This crest shines in Act 2, where the difficulty curve begins to steepen. Its Silk-powered utility provides versatility, especially in encounters where adaptability is the difference between triumph and retreat.

Hidden Secrets and Lore Implications

Explorers have noted oddities within the chapel. Playing the Needolin—Silksong’s equivalent to the Dream Nail—sometimes triggers spectral feathers or ephemeral illusions, hinting at deeper lore connections.

Some players report finding a breakable wall in the room, though returning later often leaves them locked out. While these events may not yield tangible rewards, they suggest the Chapel of the Architect holds symbolic weight within the world’s mythology, tying into the enigmatic role of the Architects themselves.

Key Notes & Tips

Don’t Rush: Ensure you’ve collected enough tools before seeking out the Twelfth Architect.
Resource Management: Keep at least 110 Rosaries set aside if you want the key as soon as you encounter him.
Optional Lore: Experiment with the Needolin inside the chapel for subtle narrative flourishes, even if they don’t grant items.

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