It is part of the series 'Invisible' and it is followed by the book 'Unsolved' (2019) Emmy Dockery is an FBI research analyst on leave.

She has been obsessed with a large number of fires in which a single person always died, including one involving her sister.

Local authorities, finding no foul play, ruled all these fires were accidental.

By continuing to insist these explained fires were really murders, she has put her career with the FBI in jeopardy.

"[5] It was also on the New York Times Best Seller list for "Combined Print & E-Book Fiction" soon after it was released.