To save her sister and her faithful student, Celestia herself must travel into the ancient tunnels beneath the ruined castle in the Everfree Forest. She, and the guards who accompany her, must face the dark, twisting corridors. Still, what was Luna and Twilight's purpose at the old castle? Why were they unable to return of their own accord?And what watches Celestia from beyond the light's edge?
- Adult Fear: This fic is full of them: a very close relative and a very close friend both are missing for days, an unidentified being is killing your companions, and you are lost in a pitch dark tunnel with no escape, no food and no water while waiting for your companions to return and surviving on meat from your companion's dead body (while you're a herbivore) for days!
- Black Magic: The Clavicula Concorida Regis is said to contain evil spells meant to control monsters.
- Darker and Edgier: It was written as a horror.
- Dark Fic
- Demonic Possession: What Tirek attempted to do with Celestia.
- Living Shadow: The darkness in the tunnels. It can actively kill any unsuspecting pony inside the tunnels.
- Make Me Wanna Shout: Celestia used her Royal Canterlot Voice to knock down attacking skeletons in the tomb.
- Sanity Slippage: What happened to poor Fortress as she waited for what felt like an eternity (literally) for reinforcements to arrive.
- Sealed Evil in a Can: The Living Shadow in the tunnels were demons trying to free their master, Tirek, from Tartarus.
- Vitriolic Best Buds: Path Finder and Night Glaze.
- Wham Line: Those who have been touched by Tirek are forever within his grasp.