For years, fans have watched The CW's "Arrowverse" shows and wondered where Batman is -- and tonight on "Elseworlds," they got their answer.
The Dark Knight was indeed the first vigilante on Earth-1, pre-dating even Oliver Queen in the rich-kid-punches-bad-guys genre. However, according to tonight's episode, he has been missing in action for three years.
Given that a big part of "Elseworlds" was setting up the origin of Batwoman, it must be noted that the modern era's first appearance of Batwoman came during 52 -- a story in which Superman, Batman, and Wonder Woman were gone and the DC Universe had to make do without them.
It was not too hard for Batman go to missing in the Arrowverse, since he was not a publicly-known figure and (as in many takes on the early days of Batman) was widely dismissed as an urban legend. Oliver Queen was one of the people who referred to him as such, although that may be a sense of frustration at not being the "original vigilante," as he called himself in tonight's episode.
Bruce Wayne was referenced in the Arrowverse in the infamous newspaper from the pilot episode of The Flash, where his company was reported to have merged with Queen Enterprises.
Later, Oliver Queen joked that he was no more the Green Arrow than Bruce Wayne was, a line that blew up the internet and caused a new round of speculation that we might one day see the Dark Knight in the Arrowverse.
Rip Hunter famously said in one of the earliest episodes of DC's Legends of Tomorrow that he had seen "Men of Steel die and Dark Knights fall."
And there have been several references to Batman -- never by name, and always oblique -- on Supergirl, including an intimation that her cousin might be friends with him...something that tonight's episode confirmed when Kara said as much to Kate.2comments
And, yes, Gotham City has been mentioned or named on a sign in at least one episode of each show.
The "Elseworlds" crossover will take place across three nights, kicking off on Sunday, Dec. 9th on The Flash at 8 p.m. ET. It continues on Arrow Monday, Dec. 10th at 8 p.m. and then finishes up on Supergirl Tuesday, Dec. 11th at 8 p.m. ET.