Guardians of Time is a trilogy of novels written by Marianne Curley. The plot of the trilogy consists of the Guardians of Time (the Guard), trying to protect the past, present, and future by traveling into the past to thwart their enemies, the Order of Chaos (the Order), who are trying to change past events to give themselves more power. The original books in this trilogy are The Named, The Dark, and The Key. In 2018, Curley added a fourth book to the series by publishing The Shadow.