|“||This place, wherever it was, was freezing, deserted, barren. Only rock and grass and mist and sea.||”|
The Prison is situated in a cavernous mountain on the island. There is a sharp grassy slope leading to the entrance. Veils of chilled mist waft past. The land sweeps away to brutal cliffs and a violent, pewter sea. The enormous mountain is wide and flat-topped, made of gray stone and moss. The island is freezing, deserted, and barren. There are only rocks, mist, and the sea.
There are incredibly strong wards surrounding the Prison that keep anyone from winnowing inside or flying to the entrance, the wards demand that visitors walk in the long way.
The climb up the slope of the Prison is so steep at times that one must crawl on hands and knees. There are countless little streams that gurgle though the bumps and hollows in the moss-and-grass slopes. The wind whips by with a hollow moan.
The entrance is in the upper face of the mountain. There is nothing but grassy slopes sweeping behind, far below, to where they flowed to the sea. With the touch of the High Lord of the Night Court's blood, the stone vanishes in a ripple of light. Pale, carved gates of bone are revealed. They're so high their tops are lost to the mist.
Upon entering the Prison, there is a cavern of black so inky, there is nothing else like it. The Prison is guarded by beings that are nothing but shadows of thought and an ancient spell. They dwell within the rock of the mountain, and only emerge at feeding time, or to deal with restless prisoners. The Prison is said to be law unto itself, and that it may as well be an eighth Court. However it officially falls under the Night Court's jurisdiction, and Rhysand's blood is keyed to the gates.
Once someone is sentenced to the Prison and pass through the gates, they belong to the Prison. No one can free a prisoner, not even the High Lord of the Night Court.
No prisoners have been able to escape the Prison, except for Amren who found a loophole in the spell by binding herself to a new body and successfully freeing herself.
Rhys has sentenced someone to the Prison. It is mentioned that Cassian has carried out the sentencing of someone to the Prison.
Feyre Archeron and Rhysand visit the Prison after Feyre agrees to work with Rhys and his Inner Circle against Hybern. They want to speak with one of the prisoners, the Bone Carver. The first time they try to go, the thought of going underground triggers Feyre and they return to the town house in Velaris. After Amren gives Feyre a necklace that she claims helped her escape the Prison and will allow Feyre to not end up trapped, Rhys and Feyre are able to visit the Bone Carver.
Before they enter, Rhysand tells Feyre not to say anything that she doesn't want others hearing because the inmates don't have anything better to do than to listen through the earth and rock for gossip. They will sell any bit of information for food, sex, maybe a breath of air.
Nesta Archeron is drawn to the Prison during her search for the Dread Trove. She and Cassian travel there to retrieve The Harp. Once inside the chamber where the Harp is, the door to Lanthyss' cell opens. Cassian distracts him while Nesta runs for help. Once she si outside, she decides to use the Harp to go back to Cassian, where she slays Lanthys usign Ataraxia. The other occupants in the Prison felt his death, and start screaming to be spared from Nesta and her sword. Nesta promptly uses the Harp to take her and Cassian to Velaris.