On the surface, this week's all-new episode of Arrow teases Bronze Tiger's (Michael Jai White) plan to sell Malcolm's (John Barrowman) earthquake machine (the one that decimated The Glades at the end of Season 1) to the highest bidder. But the installment, titled "Tremors" and written by executive producer Marc Guggenheim and co-executive producer Drew Z. Greenberg, also slyly sets up seismic events that threaten to shake up the foundations that The CW superhero series is firmly built upon.

But first, to recap: Roy (Colton Haynes) been injected with a mysterious serum called Mirakuru (roughly translated as "The Miracle") that kills 99.9% of dosed subjects. But, if a subject actually survives the transition, they're imbued with superhuman abilities: strength, endurance, durability, reflexes, healing, and speed. In short, they're superhero ready.

However, Oliver (Stephen Amell) learned the hard way that Mirakuru channels itself through rage, so he's begrudgingly taken Roy under his wing after watching his former ally, Slade Wilson (Manu Bennett), succumb to the serum's side effects. "Through Roy's training, Oliver has a chance to revisit some old sins," Guggenheim told BuzzFeed, not just referencing Slade, but also The Huntress (Jessica De Gouw).

"He failed miserably to be a guide for The Huntress, so now he's setting out to do this right," Guggenheim added. "We always want to be consistent with what we've already established for any character that has a superhero destiny. If it was as easy as putting on a costume and fighting crime, then anyone could do it. It took five years of hell to turn Oliver into The Arrow. It took five years of hell, and The League of Assassins, to turn Sara [Caity Lotz] into The Black Canary. It's not that Roy couldn't be a member of Team Arrow without the Mirakuru; it's that he couldn't do these things without going through the crucible the Mirakuru establishes."