Based around Jack's life; alone, with other spirits, and the Guardians. There will be an overarching plot that develops over the chapters. Warning: there will be some violence and death involved in some of the later stories.
This takes place after Rise of the Guardians. You are reading in the perspective of Pitch Black's daughter. Instead of inheriting your father's powers, the Man in the Moon gifted you with the power to instill courage in mortal children and adults alike.
The reader knows the first four Guardians already, but when she teams up with them to defeat Pitch, she is introduced to Jack Frost.