Due to the unknown explosion, the earth has become a difficult world to live in.
The explosion caused cracks in the dimension and caused Abyss (dimensional cracks) called abyss throughout the Earth.

In Abyss, monsters and migrants flowed in from different levels, and APEX, which ruled the Earth before the explosion, began to control Abyss.

A civilian organization called Voltaire has begun to emerge to counter the riots in APEX, and you are the commander of Voltaire.

- Summon the heroes from the abyss and respond to APEX!
- Supply the heroes!
- Build a weapon and build a stronger unit!
- Meet your friends online!