'Arrow' Diggle Green Lantern: "Elseworlds" Almost Confirms a Big Fan Theory

The Arrowverse crossover “Elseworlds” is rewriting reality, which didn’t leave any time for Arrow to include flashforwards in this week’s episode. However, we do still get a tease of what could be John Diggle’s future based on his present in another dimension. It also confirms a popular fan theory, at least one Earth in the multiverse.

Spoilers for Arrow Season 7 Episode 9 “Elseworlds, Part 2” below.

The “Elseworlds” crossover began on The Flash, but the red skies and lightning in Central City moved to Star City between Parts 1 and 2. On Arrow, Felicity notices the energy discharge of the lightning looks like a dimensional breach and makes a magnet that draws whoever’s trying to breach through to them.

When she, Diggle, Caitlin, Cisco, and Curtis turn it on, they briefly see Earth-90’s Flash in a breach. He tells them they have to get the book to fix everything.

The book in question is the one the Monitor gave John Deegan to rewrite reality, which resulted in Oliver and Barry swapping lives. Oliver, Barry, and Kara track Deegan down at Arkham Asylum, and get the book back with Batwoman’s help.

While they’re still working to unlock the book, however, Earth-90’s Flash comes through a breach. This Barry Allen greets John Diggle by name but notices something’s missing.

“You’re not wearing your ring,” he tells him. “Things must be different here.”

That means on Earth-90, John Diggle is John Stewart, a.k.a. the Green Lantern. It’s been a popular fan theory for years ever since the actor himself confirmed the possibility, but don’t get too excited just yet. This doesn’t necessarily mean we’re going to see our John Diggle get his own power ring and abilities, which is too bad because given Diggle’s reaction to powers, who wouldn’t want to see how he reacts to having them himself?

In an interview with The Wrap, showrunner Beth Schwartz teased Diggle’s possible future in the Arrowverse.

“We’re all really excited about that,” she said. “I’m not sure what’s to come of that… it’s not been written yet.”

For now, that’s likely going to be the only hint of John as the Green Lantern, at least in the immediate future. At the end of “Elseworlds, Part 2,” before instructing John Deegan to rewrite reality again, the Monitor sends Earth-90’s Flash away in a puff of smoke with breach properties. (We’re assuming he’s still alive, since the Monitor uses the same smoke to return Kara back near the others when she tries to run at him.)

On Earth-1, John Diggle may remain Spartan in the present and future, but at least on Earth-90, we know he’s the Green Lantern. We’re assuming he’s alive, since he wasn’t seen among the fallen heroes on that Earth in the opening scene of the crossover and Barry would’ve likely had a different reaction upon seeing him.

But you never know what could happen. After all, look at Star City in the future. As the flashforwards have shown, the future is bleak and we have yet to see what happened to John Diggle.

“Elseworlds” concludes on Supergirl on Tuesday at 8 p.m. on The CW.

Related video: “Elseworlds” Arrowverse Crossover Extended Trailer Shows Batwoman Out of Costume