Walking through Tarios's glass-blowing workshops, Tris discovers Kislun Warder, a journeyman suffering from the effects of a lightning strike who wields a mixture of ambient glass and lightning magic. Tris has to teach him - because there are no other lightning magicians in Tarios. The intensity of passions is increased by the fact that a serial killer is operating in Tarios, and local law enforcement officers are powerless: due to the institutionalized thanatophobia of local residents, all efforts to catch the criminal are in vain. There is only one hope - lightning balls made of glass that predict the future, which Kislun can make.