If you’re a fan of Arrow and have been wondering just where Walter Steele has been, you may be surprised to find out he’s become a terrorist on Krypton. No, this doesn’t mean there’s a new Arrowverse crossover (yet), but eagle-eyed DC fans were in for a surprise on the newest episode of Syfy’s Krypton.

In the latest episode of Krypton on Syfy, “The Rankless Initiative,” Arrow alum Colin Salmon appears as an unnamed super criminal who is part of a terrorist cell called Black Zero. In the episode, Lyta Zod is debriefed on their new enemy, who appears via hologram.

Though Salmon’s character is not yet named, there’s speculation he could be Jax-Ur, who in comics called himself the worst criminal in the Phantom Zone. If that’s the case, Krypton is taking some major liberties, as Jax-Ur once helped Superman defeat Black Zero, who at the time wasn’t an organization but one single villain who claimed responsibility for destroying Krypton.

The name “Black Zero” has also been shared by other villains, terrorist groups, and even a computer virus. In the 2013 film Man of Steel, it was the spaceship that carried General Zod through the Phantom Zone. (Jax-Ur was also in Man of Steel as one of Zod’s allies, played by Mackenzie Gray.)

Arrow Colin Salmon Krypton
Colin Salmon (left), in the first season of 'Arrow.'

But for most DC fans, Black Zero’s moment in Krypton is noteworthy because of Salmon, who had a recurring role in the CW’s Arrow as the wealthy Walter Steele. In Arrow, Walter married the Green Arrow’s mother, Moira Queen, after her husband Robert — patriarch to the Queen family and head of Queen Consolidated — died in the remote island of Lian Yu, where Oliver trained to become the Green Arrow. Salmon’s final appearance as Walter was in the Season 2 episode, “City of Blood.”

There is no direct connection between Krypton and the Arrowverse, outside of the fact the shows adapt an array of stories from DC Comics. And given how Gotham on FOX hasn’t bitten the crossover bug, it’s unlikely the shows will ever meet. Krypton showrunner Cameron Welsh told Inverse that this Superman show is specifically not part of the Arroweverse, shortly before the debut two weeks ago. “We’re on our own,” he said. -**Krypton airs Wednesdays at 10 p.m. on Syfy.**