Location Overview
The Exhaust Organ is a pivotal location in the Bilewater Region of Hollow Knight: Silksong. This steam-filled industrial area serves as one of two possible routes to complete Act 1, offering an alternative to the Blasted Steps path. Here, Hornet must navigate through hazardous steam vents while battling Drapelords and ultimately face the Phantom boss - a darker reflection of herself.
Successfully completing the Exhaust Organ rewards players with the powerful Cross Stitch skill, one of the most valuable abilities in the entire game, which enables parrying enemy attacks and delivering devastating counterstrikes.
Getting to the Exhaust Organ
To reach the Exhaust Organ, you must first complete The Mist puzzle in Bilewater. This involves following white butterflies throughout the randomized rooms and playing your Needolin near them to reveal the correct path forward.
Pro Tip: The Mist rooms are randomly generated, so you can't memorize the layout. Always look for the butterflies - they are your key to progressing through this area.
Complete Walkthrough
Step 1: Unlock the Bench
Upon entering the Exhaust Organ, immediately prioritize finding the bench for a safe respawn point. Head right past the first Drapefly enemy until you reach some platforms.
How to Reach the Bench:
- 1. Enter the main chamber and head right
- 2. Climb up the platforms in the central area
- 3. Move left using Cling Grip to scale up
- 4. Attack the cobwebs covering the bench to clear it
- 5. Rest at the bench to unlock it as a respawn point
Step 2: Navigate the Steam Passages
The Exhaust Organ's signature challenge involves navigating through passages filled with periodically blasting steam that deals 2 Masks of damage.
Steam Navigation Tips:
- • Watch for safe ledges along the walls where you can take shelter
- • Use Cling Grip to quickly move between safe spots
- • Time your movements during the gaps between steam blasts
- • Be careful of spikes along the walls while climbing
Step 3: Collect the Silkeater
After navigating three steam-filled passages, you'll reach a crossroads. Drop to the bottom and head right to find three cocoons containing a valuable Silkeater.
Collectible Alert: The Silkeater is a consumable that permanently increases your Silk capacity. Don't miss this valuable upgrade!
Step 4: Create the Bench Shortcut
After collecting the Silkeater, climb back up and take the first left to find a wooden barricade. Attack it repeatedly to break it down and create an elevator shortcut back to the bench area.
Step 5: Rescue the Lost Flea
From the top of the passage, head left to find a hidden passage that leads outside. Platform across while avoiding the maggot-infested water to find a Lost Flea trapped in tree branches.
Secret Discovery: The passage might seem like a dead end, but continue moving left past the wall to reveal the hidden route outside.
Phantom Boss Battle
Boss Overview
The Phantom is a dark reflection of Hornet herself, wielding similar abilities but with a twisted, shadowy appearance. This boss serves as the climactic encounter of the Exhaust Organ and acts as an alternative to The Last Judge for progression into Act 2.
Attack Patterns
Phase 1 Attacks:
- • Needle throw with large recovery window
- • Basic slashing attacks
- • Dash attacks across the arena
- • Exhaust burst attacks from the environment
Phase 2 Changes:
- • Adds one additional attack pattern
- • Slightly increased aggression
- • More frequent use of environment
- • Maintains same damage output
Strategy Guide
Winning Strategy:
- 1. Positioning: Stand on the east side of the arena to avoid exhaust bursts
- 2. Attack Windows: Both needle throw and basic attacks provide large openings for damage
- 3. Pattern Recognition: Learn the timing between attacks to maximize your damage output
- 4. Special Finish: The final hit will always be parried, triggering a cutscene where you must press the SILK SKILL button
- 5. Patience: The boss only deals 1 Mask of damage per hit, so focus on consistent damage over risky plays
Important: The Phantom boss fight concludes with a dramatic cutscene where Hornet and Phantom clash. When prompted, press the Silk Skill button to execute the finishing parry and claim victory.
Cross Stitch Skill Guide
Skill Overview
Cross Stitch is a powerful counter-parry skill that consumes 4 bars of Silk to enter a defensive stance. When an enemy attacks during this stance, Hornet negates all damage and immediately performs a devastating cross-shaped area-of-effect counterattack.
Detailed Mechanics
Parry Requirements:
- • Must match the direction of incoming attacks
- • Needle hitbox must contact the enemy's weapon
- • Works on melee and ranged weapon attacks
- • Cannot parry body-based attacks (like crushes)
Combat Benefits:
- • Base damage: 52 (92 with Shaman Crest)
- • Long-range cross-shaped AoE attack
- • Brief invincibility frames after parry
- • Effective against multiple enemies
Advanced Tips
Mastery Guidelines:
- • Timing Practice: Observe enemy attack animations carefully for wind-up cues
- • Directional Matching: Horizontal attacks need horizontal parries, vertical attacks need upward strikes
- • Risk Management: You have minimal invincibility frames after parrying, so position carefully
- • Silk Management: At 4 Silk bars per use, plan your parries strategically in longer encounters
- • Enhancement Priority: Consider getting Shaman Crest to nearly double the damage output
Pro Insight: Cross Stitch remains one of the most valuable skills throughout the entire game. Its combination of defensive utility and offensive power makes it essential for surviving later boss encounters and challenging areas.
Items and Rewards
Collectibles:
- • Silkeater: Permanent Silk capacity increase
- • Lost Flea: Rescue quest completion
Skills & Abilities:
- • Cross Stitch: Powerful parry-counter Silk Skill
- • Act 2 Access: Progression to Citadel areas
After Defeating Phantom
Upon defeating the Phantom, you'll gain immediate access to several new areas and opportunities:
Next Steps:
- 1. Head left from Phantom's arena to reach and activate an elevator
- 2. Ride the elevator north to access upper areas
- 3. Attack the lever to open doors and continue left
- 4. Use Cling Grip to ascend the spike-covered passage
- 5. Reach the Grand Bellway Bench and Bellway Station
- 6. Access your first Ventrica Station for fast travel
- 7. Begin exploring the Choral Chambers in the Citadel
The victory over Phantom opens a streamlined route to major travel hubs and grants direct access to Act 2 content, making this one of the most rewarding boss encounters in the early game.
Mastering the Exhaust Organ
The Exhaust Organ represents a perfect blend of platforming challenge, combat mastery, and meaningful progression in Hollow Knight: Silksong. From navigating the treacherous steam-filled passages to conquering the formidable Phantom boss, this area tests every skill you've developed throughout Act 1.
The rewards for your perseverance are substantial: the Cross Stitch skill becomes an indispensable tool for the remainder of your journey, while the direct access to the Grand Bellway opens up new exploration possibilities. Whether you choose this path or the alternative Blasted Steps route, the Exhaust Organ offers one of the most satisfying and impactful sequences in the early game.
Cross Stitch becomes one of the most valuable skills throughout your entire Silksong journey!
Guide accurate as of September 2025 based on community research and testing