Astrolab

Access and exit
The Astrolab can only be accessed from the Throne Room when playing with 5 BSC active.

In order to reach the exit, the player needs to collect a series of keys by beating Elite enemies. An Elite Failed Experiment and an Elite Slammer drop the and the  respectively, which can be used to reach a room where two Elite Slammers are waiting. Upon defeating them, they each drop a, which are needed to open the doors to the Observatory.

Scrolls
The Astrolab contains 2 Dual Scrolls.

Enemy tier and gear level scaling
In the table below, you will find the gear level and enemy tier of the Astrolab based on difficulty. Even though the Astrolab can only be accessed on Hell difficulty there are enemy tiers set for lower difficulties.

Chests and loot

 * 1 Treasure chest

Shops

 * 1 Weapon/Skill shop
 * 1 Food Shop

Secret area
A hidden tower located under a corridor contains the behind a series of traps, which can be used to retrieve the blueprint for the.

Enemy blueprints

 * The blueprints for can be looted from Magistrates of Death.
 * The blueprints for can be looted from Defenders.

Enemies
The Astrolab is home to two unique enemies: Magistrates of Death, Defenders, and Librarians. In addition to them, the Astrolab is also home to Failed Experiments, Slammers and Bombers.

The table below lists which enemies are present in the Astrolab and which blueprints each may drop.

Crow experiment room
A room filled with empty crow cages hanging from the ceiling and a broken vat with a tap and a half filled filled flask standing beneath it. There is a desk with a grimoire of the Alchemist. This room is likely the explanation behind the existence of Slammers.

Research notebook

 * "Against all odds, this solution created mutations in the infected crows instead of curing them."
 * "Some subjects managed to escape by breaking the bars of their cage!"
 * "God only knows where they are now... I hope their condition has stabilized now."

Solution
When examined the Beheaded notes:
 * "Another failed cure..."
 * "How many crows drank this solution?"

Cage
When examined the Beheaded notes:
 * "All these broken cages..."
 * "Those crows give me the creeps!"

Moonlit lab
A large room which is half-occupied by a laboratory setup containing a grimoire and various notes on the wall. The other half features a large body suspended in an incubator in front of an even larger arched window.

Alchemist grimoire
The Alchemist leaves the following on his research notebook:
 * "I hope looking at the stars will allow me to greatly advance my research..."
 * "Bodies always act different during a full moon."

Notes on the wall
When examined the Beheaded notes:
 * "Some weird sketches... Planets, stars, constellations."
 * "The Alchemist really went down every path to find a cure."

The Beheaded then nods repeatedly and offers a thumbs up before exclaiming:
 * "How selfless of him!"

Cell vat
When examined the Beheaded notes:
 * "The body bathes in moonlight..."
 * "... It does feel good, this light, when the moonlight is reflected off wisps of fog."

Trivia

 * Although not through normal gameplay, it would be possible to access the Astrolab in any difficulty: the level is present in the .json files for all the difficulties.