Series
Underworld
OngoingSummoned into the lightless tunnels of the Underworld along with hundreds of other teenagers — as prey — Elorion has one absurd advantage: a System interface and the stubbornness to grind it. Staying alive means leveling faster than the things hunting him, and forging his fellow captives into something like an army. Apollos Thorne's claustrophobic descent-and-ascent power fantasy.
Reading order
Common questions
- How many books are in Underworld?
- Underworld has 8 cataloged books, beginning with Level Up or Die! (2017). The most recent volume is Underworld - The Succubi (2025).
- What is the reading order for Underworld?
- Read Underworld in publication order: 1. Level Up or Die! · 2. Through the Belly of the Beast · 3. Sanctuary · 4. Proving Grounds · 5. Vampire Gate · 6. Scorching Sun · 7. Underworld - Sanctuary 2.0 · 8. Underworld - The Succubi.
- Is Underworld finished?
- Not yet — Underworld is ongoing. Underworld - The Succubi is the most recent cataloged volume.
- Who writes Underworld?
- Underworld is written by Apollos Thorne.
- Is Underworld on Kindle Unlimited?
- Yes — every cataloged volume of Underworld was on Kindle Unlimited at our last check.
- Is Underworld available as an audiobook?
- Yes — all 8 volumes have audiobook editions.
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