Who could have imagined back in 2012 when CW debuted “Arrow,” about a middling superhero unfamiliar to many viewers, that it would eventually spawn a rich prime time world encompassing several series and featuring dozens of colorful champions?

The Marvel universe has dominated multiplexes with 22 films (and counting), but DC has been less successful with its own cinematic combo platters — the rumored “Snyder cut” of “Justice League” notwithstanding. But on TV it’s been a different story, as the “Arrowverse” has expanded to include multiple CW series, adding “The Flash” in 2014, “Supergirl” (which began on CBS) in 2015, “DC’s Legends of Tomorrow” in 2016 and “Batwoman” this year.

Along the way it has also leaned into its comic-book roots, fully embracing many of the art form’s shenanigans: Time travel! Doppelgängers from parallel worlds! Unexpected (and expected) resurrections!

All of this comes to a head in “Crisis on Infinite Earths,” a five-part crossover story that begins Sunday in “Supergirl,” then continues Monday in “Batwoman” and Tuesday in “The Flash” before concluding on Jan. 14 in “Arrow” and “DC’s Legends of Tomorrow.” The story is inspired by 1985’s Crisis on Infinite Earths, a 12-issue comic book series about a cosmic villain out to destroy all parallel worlds. The story, which was published to help celebrate DC’s 50th anniversary and to bring in new readers, united heroes cherry-picked from the company’s five decades to stop the threat.