VANCOUVER, British Columbia — Greg Berlanti, watching from a distance, couldn’t stop smiling as he sidled up to members of his creative team on the set here of “Arrow” — his second-season CW network adaptation of the “Green Arrow” comic book character — gushing like the adolescent fanboy he used to be.

“Can you believe this?” he said in a giddy whisper, trying not to disrupt the filming. “It’s the first time Green Arrow meets the Flash!”

Mr. Berlanti, 41, the show’s creator, made his reputation as a prolific writer and producer of character-driven family dramas, including “Dawson’s Creek,” “Brothers and Sisters,” “Jack and Bobby,” “Dirty Sexy Money” and one he created, “Everwood.” But his most recent television success has been rooted in superheroes and fantasy tales, the genres he adored as a comic-book-obsessed kid growing up in Rye, N.Y.

Which is why he was so excited to see two of his favorite characters from the classic DC Comics universe, not yet superheroes but on the verge, meeting in a scene that he had imagined and that his team — including the “Arrow” executive producer Andrew Kreisberg, and the comic book writer Geoff Johns, DC Entertainment’s chief creative officer — had brought to life. There was Barry Allen, just a particle-accelerator mishap away from becoming the Fastest Man Alive, introducing himself to wounded-soul billionaire Oliver Queen, who spends his off hours fighting crime with high-tech bows and arrows.