Molly Mavity and Pepper Yusef are dealing with their own personal tragedies when they are tasked by an anonymous person with solving the decades-old murder of Ava Dryman, an East German teenager whose diary was published after her death.

Molly Mavity doesn't believe her mother killed herself three years ago-- or that her father is about to be executed for his crimes. Pepper Yusef is a Kuwaiti immigrant with a seizure dog, and is about to fail out of school. They are tasked with solving the decades-old murder of Ava Dryman, an East German teenager resistance fighter whose death led to the destruction of the Berlin Wall.