Shin Sihyun has never been lucky.

The day the Illusion Tower crashes into Seoul, his brand-new café is the first thing it destroys. Somehow, his terrible luck carries him to a hidden floor where an eccentric archmage decides to make him a disciple—and after surviving a training regimen that should have killed him, Sihyun walks away as a master of poison.

While other climbers dread venom and curses, he treats them like ingredients. Before long, his custom poisons, monster products, and bizarre business ideas are dominating the Tower's auction house, leaving climbers everywhere asking the same question:

"Poison King, how much are you charging today?"