The Cogwork Heart forms after collecting three Cogheart pieces from memory bell chambers scattered across the Citadel in Hollow Knight: Silksong. Each chamber presents a bell sequence you must repeat; assembling the Heart lets you revive a sleeping automaton in Cogwork Core and ultimately start the Final Audience wish.

Requirements and quick prep

Collecting all Cogheart pieces and installing the Heart requires movement skills. You will need Double Jump to reach the automaton in Cogwork Core and to access the Memorium chamber. Dash is strongly recommended for bell platforming.

All three Cogheart chambers use the same rule: watch the bells ring, then strike them in the exact order shown. Writing the numbers down or calling them out helps avoid repeats.

Cogheart piece 1 — Choral Chambers

This first chamber sits in Choral Chambers and uses a two‑phase bell sequence.

Step 1: Reach the memory bell room in Choral Chambers. Look for a central platform with seven bells arranged around the arena.

Step 2: Trigger the puzzle and focus on Phase 1. Strike the bells in this order: 3, 6, 5, 1, 7. Missing a note resets the current phase.

Step 3: Start Phase 2. Strike the bells in this order: 2, 4, 6, 3, 5, 1. Move deliberately to avoid accidental bell hits.

Step 4: Collect the Cogheart piece that appears at the center of the room. Exit when you’re ready.

Cogheart piece 2 — Whispering Vaults

The second chamber is deeper in Whispering Vaults and has three phases with longer patterns.

Step 1: Navigate through Whispering Vaults to the bell puzzle room. Expect some light route manipulation and moving block interactions en route.

Step 2: Complete Phase 1 with this order: 1, 2, 7, 4. Keep Hornet’s position centered to shorten movement between bells.

Step 3: Complete Phase 2 with this order: 7, 5, 5, 4, 5. Note the repeated “5”; pause to confirm ring count before moving on.

Step 4: Complete Phase 3 with this order: 2, 7, 3, 5, 6, 1. Claim the Cogheart piece that spawns in the middle.

Cogheart piece 3 — Memorium

The final chamber is in the Memorium, a hidden area accessible from Cogwork Core. Double Jump is required.

Step 1: From the Cogwork Core elevator, search to the right for a concealed route that leads into the Memorium. Expect vertical movement and light platforming.

Step 2: Begin Phase 1 with this order: 3, 5, 7, 2. Some bells sit on awkward ledges; Dash helps maintain rhythm.

Step 3: Complete Phase 2 with this order: 7, 5, 6, 7, 1. Stabilize on safe ground before each strike to avoid slips.

Step 4: Finish Phase 3 with this order: 6, 4, 2, 5, 3, 1. Pick up the final Cogheart piece that appears in the center.

Assemble and install the Cogwork Heart (Cogwork Core)

With all three pieces collected, the Cogwork Heart forms and can be slotted into a dormant automaton in Cogwork Core.

Step 1: Return to Cogwork Core and locate the bench area. From the bench, drop down into the machinery shaft to re‑enter the main core.

Step 2: Move left into the adjacent room from the lower level. Keep an eye on the ceiling for a climbable opening.

Step 3: Use Double Jump to reach the upper passage. Clear debris blocking the way to proceed rightward.

Step 4: Approach the automaton sealed in glass. Break the glass casing to access its interface.

Step 5: Insert the Cogwork Heart. The awakened Sentinel departs and begins appearing across the Citadel, engaging local enemies.

Unlock the Final Audience wish

Final Audience is tied to sightings of the revived Sentinel in the Citadel and becomes available after sufficient encounters.

Step 1: Explore the Citadel and look for the Sentinel fighting enemies in major corridors. You need to spot it twice after revival for the wish to become available.

Step 2: Prioritize high‑traffic promenades, including the long halls above the “Choral Chambers” label on the map. If you miss it, loop the area again.

Step 3: After the second sighting, rest at a bench to update state. This helps register the encounter chain.

Step 4: Travel to Songclave and check the first shrine to claim the Final Audience wish. If it has not appeared, continue patrolling Citadel routes and rest again.

Troubleshooting and tips

  • Missing bells or unreachable platforms. Return with Double Jump and Dash; several bells require precise aerial control.
  • Memorium access unclear. From the Cogwork Core elevator, probe the right‑hand wall for a concealed path into the area.
  • Sentinel isn’t spawning. Circle prominent Citadel corridors (upper and lower long halls), then rest at a bench to advance encounter tracking.
  • Puzzle repeats after a mistake. Each missed note resets the current phase; write the order down to speed retries.
  • Lost route through Whispering Vaults. Use moving blocks to open side paths, then head into the left‑side bell room with the memory switch.

Once the Heart is installed and the Sentinel is sighted twice, Final Audience opens cleanly in Songclave. Finish the wish to wrap this chain and move your progression forward.