Old Observatory Area 2 Guide

Old Observatory is The Mystery of Arpeggio Fault's Stage 2 Area in Zenless Zone Zero (ZZZ). See the Area 2 guide for each floor, the quest walkthrough, and the rewards here!

The Mystery of Arpeggio Fault Event
Fault Surface		Old Observatory		Outpost Beacon
Laboratory Ruins		Turbulent Corridor		Bangboo Password
Slumbering Land Quest			Where the Mystery Went Quest

Old Observatory Stage Details

The Mystery of Arpeggio Fault Stage 2 Details and Floors

Recommended Data File

Data File	Data File Details
Demolition Squad	Initial Effects Receive bomb-related Sub Strategies when levelling up.
	Full Effects • Explosive Stamina Immediately obtain 8 bombs • Explosion Expert Bombs deal +10 DMG to enemies, explosion length +2 • High Explosives Protagonist gains +50 HP. • Detonate and Dominate Bombs will explode immediately. Protagonist ATK +1 when detonating a bomb • Blast Suit Take no DMG from detonations, instead recovering 5 HP

Old Observatory Area 2 Guide

Arpeggio Fault Area 2 Strategy

1. Collect Contribution Points at the Start
2. Get All the Cross Blast Bombs
3. Get Silk From Merchants
4. Take Advantage of Rest Areas
5. Carefully Choose Buffs

Collect Contribution Points

In the first few floors, collect as many Contributions Points to either upgrade to two Agent helpers or to get higher tier Agents who can support you within Area 2.

You can upgrade to get two agents by giving the Pink Gun TV Tile 50 Contribution Points.

Get All the Bombs

Get as many Cross Blast plug-ins as possible and use them sparingly on walls or tactical spikes blocking items.

Get Crimson Silk From Merchants

Merchants in the Arpeggio Fault are different from the usual Merchants in Hollow Zero. You can set bombs on them and once they disappear, in their place are numerous Crimson Silks.

Take Advantage of Rest Areas

If you have a lot of bombs, especially the Resonia, which adds two more bombs when you release one, interact with the RIP Rest Areas until they disappear.

It will spawn strong enemies but it will also release numerous rewards.

Choose Your Plug-Ins and Resonia

In this stage, it's important to choose Plug-Ins or Resonia which will increase your HP and buff your bombs. HP specifically for you and your Agents so you can withstand damage.

The Mystery of the Arpeggio Fault Unravelling Quest Guide

Head to the Old Observatory Area

Teleport back to the Scott Outpost Interior and complete all the Old Observatory Area 2 Stages.

Talk to Soldier 11

After completing all the Area 2 Stages, talk to Soldier 11 outside of the tent. Then, talk to the No.4412 Bangboo about your findings on their Master, Alowyn Mystik.

All Old Observatory Rewards

Old Observatory Hollow Zero Rewards

Stage	Rewards
Prep Area	Polychrome x30 W-Engine Energy Module x2 Denny x10,000
Shallows	Polychrome x30 W-Engine Energy Module x2 Denny x10,000
Mid-Level	Polychrome x30 W-Engine Energy Module x2 Denny x10,000
Depths	Polychrome x30 W-Engine Energy Module x2 Denny x10,000
Fault Floor	Polychrome x30 W-Engine Energy Module x2 Denny x10,000

Stage 2 Event Exclusive Rewards

Stage	Rewards
Complete all stages in OId Observatory	Polychrome x50 Senior Investigator Log x2 Denny x10,000
Upgrade you squad 20 times during exploration	Polychrome x30 Specialized Shock Chip x2 Denny x10,000
Pick up Crimson Silk a total of 20 times while exploring	Polychrome x30 Specialized Shock Chip x2 Denny x10,000

Old Observatory Information

Part of The Mystery of Arpeggio Fault Event

Old Observatory is Stage 2 of The Mystery of Arpeggio Fault Hollow Zero Event! During this stage, you must get as much bombs as possible to go through the obstacles.

The Mystery of Arpeggio Fault Event Guide

Zenless Zone Zero Related Guides

The Mystery of Arpeggio Fault Event Guide

Arpeggio Fault Quests and Stages

Areas	Related Quests
Fault Surface	The Mystery of Arpeggio Fault: Special Investigation
Old Observatory	The Mystery of Arpeggio Fault: Unravelling
Outpost Beacon	The Mystery of Arpeggio Fault: Final Puzzle Piece
Laboratory Ruins (Floor 52-64)	The Mystery of Arpeggio Fault: Corruption Crisis
Turbulent Corridor (Floor 67-81)
Laboratory Ruins (94F-B & 99F-B)	Arpeggio Fault Follow-Up Investigation - Where the Mystery Went
Turbulent Corridor (87F-B & 88F-B)	Arpeggio Fault Follow-Up Investigation - Slumbering Land

Other Arpeggio Fault Guide

Other Event Guides
Password Locations and Arpeggio Fault Secret

Other Current and Upcoming Events

All Events and Schedule