SPOILER WARNING: This article contains major spoilers for "Starling City," the Arrow Season 8 premiere.
The premiere of Arrow's eighth and final season really leaned into the Batman mythology. "Starling City" included a handful of references to the Dark Knight, up to and including an explicit mention of Bruce Wayne.
The episode picked up on Lian Yu, echoing the series premiere almost shot-for-shot. Oliver runs through the woods, then lights a pyre with a flaming arrow to capture the attention of a fishing boat nearby. The fishermen notice, clamber onto the island and walk right by Batman's mask on a pike. The Batman mask, pictured above, has an arrow through one eye, just like Deathstroke's mask did in Arrow's earlier seasons. The shot established this as a different Earth -- Earth-2, to be exact -- and implied that Batman may have spent some time on the island, though the mask is never explained in the episode.
Later in the episode, Adrian Chase -- Earth-2's Green Arrow -- quoted Bruce Wayne directly, which means the two characters have interacted in this reality. "You're from a parallel universe, aren't you?" Chase said to Oliver. "The Hood from another reality."
"How'd you know that?" Dig asked.
"Bruce Wayne once told me that if you eliminate the impossible, whatever remains -- however improbable -- must be the truth," Chase explained.
Of course, this is a quote from Sherlock Holmes author Sir Arthur Conan Doyle. Nevertheless, it shows Earth-2's version of Green Arrow was in contact with Wayne at some point. The implication here is that this Wayne leans into his detective skills, channeling his comic book counterpart. He may even be a vigilante, though this is never explicitly confirmed in the episode.
Between Batwoman and "Crisis on Infinite Earths," the Arrowverse has been steadily adding more and more Batman mythology. Indeed, Batman: The Animated Series star Kevin Conroy will play Bruce Wayne in the crossover. A "Crisis" set photo that surfaced online also appears to show a newspaper featuring Michael Keaton's Bruce Wayne on the cover. Though Batman disappeared in Batwoman's mythology, "Crisis" seems to have opened the door for Wayne to appear, if not Batman.
Airing Tuesdays at 9 p.m. ET/PT on The CW, Arrow stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Rick Gonzalez as Wild Dog, Juliana Harkavy as Black Canary, Katie Cassidy as Black Siren, Katherine McNamara as Mia Smoak, Joseph David-Jones as Connor Hawke and Ben Lewis as William Clayton-Queen.