The "Grimnoir Chronicles" is a series of urban fantasy novels written by Larry Correia. Set in an alternate history during the 1930s, the story features a world where magic exists and is used by a select few known as Grimnoir. These individuals possess unique abilities that can alter reality, leading to conflicts between magical and non-magical societies. The series follows various characters, including Jake Sullivan, a former detective with magical powers, as they navigate a world filled with danger, intrigue, and supernatural threats. The books blend elements of noir, adventure, and fantasy, creating a rich narrative that explores themes of power, morality, and the consequences of magic.