Due to commitment to other projects, Michael Rosenbaum is wearing a bald cap. In earlier episodes, the actor shaved his head to achieve the iconic bald head.
Chloe's son has a set of red and yellow arrows, a reference to Speedy, the sidekick of Green Arrow.
The Superman suit seen at the end of the episode is the costume worn by Brandon Routh in Superman Returns. However, the Smallville universe's major difference is that the suit has the emblem of the House of El on both the chest and the cape, while the one seen in Superman Returns only has the symbol on the chest. DC Comics offered the Christopher Reeve suit but producer Brian Peterson felt it "just didn't quite fit in our world".
Clark says that there is an "anti-life dark force" to which Lois replies, "Too bad anti-life equations aren't covered in physics 101." This is a reference to what is always Darkseid's end game in the comics... discovering the Anti-Life Equation in order to control the universe.
Michael Rosenbaum reprises his role as Lex Luthor for the first time since 2008. This marks the only episode in the series where Rosenbaum received a guest star credit.