We’re only two nights in, and yet “Crisis on Infinite Earths,” the five-night DCTV crossover event currently airing on The CW, has already given us appearances from Batman’s Alexander Knox, Titans’ Robin and Hawk, a red-and-green-hued Burt Ward, a grizzled Kevin Conroy Bruce Wayne and a grieving Superman played by Brandon Routh. Yet, there’s one nostalgic guest appearance that has managed to stoke excitement and speculation among fans since it was announced—buzz that, if anything, has only increased since last night.

We’re talking, of course, about the Tom Welling and Erica Durance Smallville reunion on last night’s Batwoman. Taking place over a brief, but absolutely crucial, scene that also featured Jon Cryer’s Lex Luthor, the moment gave fans a glimpse of Clark and Lois’ life after Smallville’s 2011 series finale and even offered some surprising character development for the beloved version of the iconic couple.

“We had conversations about how to best see Tom Welling again,” shares Batwoman Executive Producer Caroline Dries. “We knew that we really wanted Brandon Routh as Clark Kent in the Daily Planet. I think the Tom Welling that we all kind of picture when we think of him as Clark is on the farm, so it made sense. And the farm is still there. Tom was joking when he was there, saying things like, ‘Look, that cow recognizes me!’”

It’s pretty amazing how, eight years later, Welling still exudes the warmth and down-to-earth heroism that we associate with pre-Superman Clark Kent. While fans can and do debate the definitive live action Man of Steel, its pretty easy to make the case that Welling remains the definitive Smallville-era Clark.

“I feel like every note, even Tom’s little facial expressions (during his “Crisis” appearance) when he says, ‘Still stronger!’ are great,” says Marc Guggenheim, who served as showrunner for the “Crisis on Infinite Earths” crossover.

Of course, the big twist in last night’s scene was the discovery that Clark had purposely lost his powers, choosing to instead devote his life to raising his two kids alongside Lois. It’s in many ways a bold creative choice, but one that Welling himself seemed pretty happy with. In fact, it seems to the very thing that got him to return to the role.

“Honestly, he was terrific,” reveals Guggenheim. “We got on the phone with him and basically pitched him everything. The scene was already done, so we just emailed it to him, and he basically said to me, I love this. You guys have basically written the one scene that I can't say no to.’”

If fans still question the choice, realize that there is a creative reason for it as well, but it’ll take time for that to become clear. And while there are no announced plans for Welling or Durance to return again to the roles of Clark and Lois, the door does remain open to it within the Arrowverse, especially now that we know Smallville exists within the DC Multiverse and occupies its own important, distinct place.

“It all felt like ten years ago, in a very great way,” shares Dries. “To us, it just felt like that's his natural environment where we would see him.”

The five-part "Crisis on Infinite Earths" crossover event continues tonight at 8/7c on The Flash. The final two parts will air in January on Arrow and DC's Legends of Tomorrow.