Mystics
As Holly gets closer to the truth about the Harris family, demonic and mystical imagery becomes more prevalent. It is because of this that Holly discovers that Harris' has been using mystical powers to harvest the energy of women.
Money
Mrs. Dahl, who struggles with money but still manages to put together enough to hire Holly to find her daughter, is portrayed as one of the most honorable characters in the show. Money imagery is often associated with her character, as well as with many of the ills of the world. And as more bad things are mentioned, money imagery is often included, too.
COVID-19
Throughout Holly, which is set during the COVID-19 pandemic, there is understandably COVID-19-related imagery, including its now-infamous structure and the often-significant impacts it had on people's lives. In fact, COVID-19 prevented Holly's partner from helping her crack their case. COVID-19 is portrayed as a living, breathing thing, and when it is mentioned in the novel, it is invariably described in vivid detail, painting a picture of how awful it was.
The MAGA Movement
As Holly engages in introspection throughout the book, she frequently does so with the MAGA ("Make America Great Again") movement, created and led by Donald Trump, another common topic in the novel. As Holly delves deeper into politics, imagery surrounding the MAGA movement becomes more prevalent, reinforcing Holly's negative feelings about it.
