The story of Nexus is about a group of kids who get exposed to a side of the world they thought was only found in nightmares. As it turns out, there's a veil that separates the natural world from the spiritual. And in that spirit world, there are certain dimensions that demons reside in. As of late, the veil that keeps everything in its place is weakening. It's up to the kids to find some way to fix that so the demons stay put and don't cross over.