Even the most original of dramas can sometimes borrow from non-original sources, and so “Chicago P.D.” did in Season 12, Episode 10, “Zoe.” The episode focuses on the titular eight-year-old (Annabelle Toomy), who initially seems like the only surviving victim of a double homicide and says she’s waiting for her father, who “always comes back for her.” But a DNA test proves Zoe’s not related to “her” dead mother and baby sibling. 

Adam Ruzek (Patrick Flueger) involves himself in the case and learns that Zoe’s father is a serial killer, murdering single moms and their kids when they fail to meet his standards of perfection and using Zoe as a decoy. It’s now a race against time to stop her family-annihilating pop from murdering another single mom. While may or may not be a “Chicago P.D.” storyline fans wanted to see, it’s definitely a familiar one. In spite of adding some bells and whistles, including Ruzek’s dad, “Disco” Bob Ruzek (Jack Coleman), the basic plot here is very reminiscent of the 1987 slasher classic, “The Stepfather,” which cut a swath through theatres worldwide and spawned a horror franchise.

“The Stepfather” spotlighted future “Lost” star Terry O’Quinn in a breakthrough role as Jerry Blake, a man who takes on many identities and many fake names in pursuit of parental bliss. Blake has been a stepfather many times — but each family he creates gets blown to smithereens due to his inability to accept anything less than perfection from his families. He kills them all, changes his name and appearance, and tries again and again for that perfect suburban family, only to run into walls — and stepkids willing to kill him to protect their moms. The movie spawned two direct-to-video sequels and one remake in 2009, making good old Jerry one of the creepiest parents in movie history.

While Jerry never had his own mini-Zoe riding shotgun, he could probably take on her yet-to-be-seen father. The show hasn’t revealed his identity, and the episode leaves young Zoe hanging in the balance in foster care as the cops track down the perp, which probably means we’ll come back to her later in the season. At least at this point in time — even though it’s a well-worn horror staple — it’s hard to argue that this plot thread is another repetitive One Chicago storyline.