In Holly, King examines how surface-level appearances influence peoples’ perceptions of one another, creating impressions that don’t always reflect reality. By making a seemingly sweet elderly couple into brutal murderers, King delivers a warning against judging solely on appearances.

On the outside, Emily and Rodney Harris are put-together, respectable, and intelligent people. They have long careers at Bell College under their belts, and though Rodney is known for his eccentric views on meat and Emily rubs several former colleagues the wrong way, the Harrises are generally considered upstanding citizens. Additionally, their status as elderly, well-off white couple means that people see them as safe by default. The couple plays on these assumptions, presenting themselves as well-meaning and helpless to lure in victims.

The same surface-level judgments that allow Emily and Rodney to hide in plain sight negatively impact Holly’s Black characters. The novel touches on the murder of Maleek Dutton, a Black man killed by a police officer during a traffic stop. Maleek was killed while reaching for his phone because the officer baselessly assumed he was reaching for a gun. The officer jumped to the conclusion that Maleek was dangerous due to his race, a feature of implicit bias.