Ossuary

The Ossuary is a third level biome.

Prior to the Malaise infection, Ossuary was just a normal wing of the prison. However, after an event known as "Night of the Bloody Riots" in which many are killed, the section was dedicated to function as a refuse dump for all the corpses and set ablaze.

Access and exit
The Ossuary can be accessed from the Promenade of the Condemned, which requires the, or through the Prison Depths, which requires the.

The only exit out of the Ossuary leads to the Black Bridge, where the Concierge awaits.

Ram rune
A Slasher elite can be found here who drops the Ram rune. It disappears after being defeated once.

Scrolls
The Ossuary contains 4 scrolls, including 2 Power Scrolls and 2 Dual-stat scrolls, which cannot spawn in areas requiring the Teleport, Ram or Spider runes. On (2+ BSC) there is a bonus Power scroll. When 3 BSC are active, this biome has 2 guaranteed Scroll Fragments, and when 4/5 BSC are active, this biome has 3 guaranteed Scroll Fragments.

Enemy tier and gear level scaling
In the table below, you will find the gear level and enemy tier of the Ossuary based on difficulty.

Boss Stem Cells rewards

 * 1 BSC: Food shop
 * 2 BSC: Treasure chest

Chests and loot

 * 1 guaranteed cursed chest spawn in the level.
 * Another cursed chest can spawn in the level (10% chance).
 * 1 item behind
 * 1 item behind
 * 1 elite room
 * Chance for item to spawn behind a golden doors

Shops

 * There is a food shop behind the 1 BSC door.
 * Weapon shop.

Exclusive blueprints
The blueprint for the Marksman's Bow is found behind the 8 minute timed door located in the Collector transition area before the Ossuary (only found when entering from the Promenade). The blueprint for the mutation can be found in a secret area within the level.

The blueprint for the melee weapon Torch is looted from Spawners, which are found almost exclusively in this biome (The Derelict Distillery also contains Spawners as of v2.0). The Ossuary is also the only place where one can get the Cloud Outfit, which drops from Shockers with 3+ BSC active.

Enemies
Shockers, Thornies and Spawners are iconic enemies of this level, along with Slashers and Lacerators. On higher difficulties, the Zombies are replaced by Dark Trackers, Bombers and Failed Experiments.

In the table below, you will find which enemies are present in the Ossuary depending on difficulty level. For each enemy, any common, uncommon, rare or legendary blueprints they carry are indicated. When applicable, the minimum difficulty level for blueprint acquisition is specified in brackets.

Lore
In a quote from the Prisoners' Quarters loading screen, it was implied that Ossuary's fire produced extreme amounts of fumes and some prisoners were killed by suffocation.

''The lucky prisoners had a window in their cells... They ended up choking on the ashes from the Ossuary.''

Alchemist Grimoires
Main Article: The Alchemist

In the Ossuary, the Alchemist was applying the substance found in the walls of the Slumbering Sanctuary on bones from corpses, likely executed prisoners. The substance's effects were unpredictable and the Alchemist reflects whether his experiments are worth killing so many people.