Unrelenting - Jessi Honard - Bog

A glowing symbol painted on a crumbling wall.
Sentient smoke that chokes and burns.
An ancient magic, long hidden from the world.
Bridget''s most important job has always been protecting her younger sister, Dahlia. But as adults, their relationship has become strained.
Then, Dahlia vanishes.
Nine months later, everyone has given up hope.
Everyone except Bridget, who launches her own amateur investigation.
The search leads Bridget to something far more sinister than a typical missing persons case-a carefully-guarded plot tied to powerful, age-old magic.
To uncover the truth of what happened to her sister, Bridget must confront this dangerous world, even if it means putting her own life on the line.