WARNING: The following contains spoilers for Batman: Urban Legends #6, on sale now from DC Comics.
With DC Universe's entire 80 year history restored, Infinite Frontier has seen a wide variety of characters, once lost to previous reboots, return to continuity. While some returns have been loud and exciting, others have been quieter and much more subtle. One such restoration just occurred in a Batman story, and it's part of a major Justice Society legacy.
In the Batman: Urban legends #6 story "Solo" (by Joshua Williamson, Trevor Hairsine, Rain Beredo and Steve Wands), Barbara Gordon enlists her old friend and Birds of Prey teammate Dinah Lance to go on a special mission. Black Canary, being an expert fighter, is the perfect fit for a job at the shadowy organization T.R.U.S.T., who bought much of Batman's stolen tech during Joker War. As Dinah gains the trust of Julienne Ballantine, head of T.R.U.S.T., she learns that she has an unlikely but close connection to the organization.
Ballantine shows Dinah a painting of some of T.R.U.S.T.'s former associates, and among them is her mother Dinah Drake, the original Black Canary. Apparently, both Dinah's mother and her father, detective Larry Lance, believed in the organization's mission and worked with them for a number of years. This is a very important moment for the Black Canary legacy, as it's the first time Dinah Drake has been mentioned since the New 52.
The original Golden Age Black Canary first appeared in 1947 during Flash Comics #86 and was created by Robert Kanigher and Carmine Infantino. Dinah Drake started out by posing as a criminal to infiltrate gangs and break them down from the inside, but soon abandoned this to become a well-known costumed crime-fighter. This eventually led to her joining the Justice Society of America.
During the Silver Age, when the Justice Society characters were moved to Earth-2, Black Canary and the JSA teamed up with the Justice League numerous times. When one team up led to the death of her husband Larry, Dinah Drake migrated to Earth-1 to join the Justice League and subsequently gained her famous Canary Cry. It was eventually revealed that Canary had at some point been swapped out with Dinah and Larry's daughter with her mother's Golden Age memories implanted in her mind.
This odd story choice was retconned post-Crisis, simplifying the Black Canary legacy. Dinah Drake was the first Canary alongside the JSA and retired alongside them as well. Years later, her daughter Dinah Lance adopted the costumed persona, despite her mother's objections. Unlike her mother, Dinah was born with her Canary Cry and learned how to fight from JSA hero Wildcat.
This multi-generational superhero legacy disappeared after the New 52 reboot. With the JSA no longer a part of the main DCU, the character Black Canary became an amalgam of the mother and daughter that came before. In this new history, Dinah Drake was abandoned by her teen mother when she was four and grew up on the streets of Gotham. She was trained by Desmond Lamar, an ex-special forces soldier, rather than Wildcat.
Later in life, Dinah's skills drew the attention of the government, who recruited her to be part of their team of metahuman fighters. There she gained her Canary Cry and met Kurt Lance, her lover who she married in secret. When the government decided to eliminate her, Dinah Lance (having taken her late husband's last name) fled and began her superhero career as the Black Canary.
In the current Infinite Frontier era, the New 52 origin is no longer relevant. Now, the original history of Black Canary is back in place, as evidenced by the reference to the Golden Age hero in this story. With other JSA heroes reappearing in the DCU, it is entirely possible that the original Black Canary could now make a return to the DC universe. She died of cancer in the original continuity but other heroes have recently been resurrected by the new multiversal reboot, paving the way for the Canary to return as well.