In The Chain, mathematical patterns symbolize the supposed predictability of human nature—which The Chain leaders Ginger and Olly prey on. Although mathematical patterns are often reliable, some patterns are more stable than others—with The Chain’s links become more unstable the longer The Chain gets. Olly’s mathematical and computer programming skills lead to the creation of The Chain, but even he knows it won’t withstand exponential growth; likewise, mathematician and former link Erik comes to the same conclusion. This inevitable instability (Rachel, Pete, and Erik’s tracking of Ginger and Olly) leads to The Chain’s end. While parental love sustained the crime ring for years, like mathematical patterns that run their course, some parents reached their breaking point, especially after being denied true peace.

Pseudonyms symbolize the complex nature of identity and morality. Characters in The Chain often view themselves differently from how others view them. For example, Rachel (who has two surnames, with “O’Neill” referencing her ex-husband Marty O’Neill) doesn’t understand why someone would pick her as the newest link in The Chain, but she was targeted because she possesses the parental love and resilience necessary to complete her tasks. People such as Kylie’s kidnappers and Rachel, who are typical, law-abiding citizens, become “monsters” in the lives of the children they kidnap—thus complicating