SPOILER WARNING: The following article contains major spoilers for "The Demon," the latest episode of Arrow.
Tonight's episode of Arrow teased the return of The Demon, but it wasn't the one some fans were expecting.
After returning to his prison cell, Oliver Queen was greeted by Talia al Ghul, the daughter of The Demon, Ra's al Ghul. As surprising as her appearance may be -- she was thought to have died on Lian Yu during the season finale of Season 5, and has burn marks on her face and arms -- the detail of where she's been may have greater significance for the Arrowverse's upcoming "Elseworlds" crossover.
Once Oliver gets over the initial shock of seeing Talia alive and in his cell, he asks how she wound up behind bars. "I ran afoul of an old foe in Gotham," she said. This isn't the first time that Gotham has been namedropped on Arrow, but it is the first time Batman's hometown has come up since the announcement that Gotham City will play host to The CW's annual Arrowverse crossover.
Titled "Elseworlds," the crossover will bring together Arrow, The Flash and Supergirl along with the debuts of Batwoman (Ruby Rose), Lois Lane (Elizabeth Tulloch), Nora Fries (Cassandra Jean Amell), The Monitor (LaMonica Garrett) and Psycho-Pirate (Bob Frazer). Tyler Hoechlin will also return as Superman.
Talia does not reveal the identity of the foe she clashed with in Gotham, but there is a possibility it's someone who is set to star in "Elseworlds." If Talia was up to no good, she would more than likely attract the attention of Batwoman, who would apprehend The Demon's Daughter, resulting in her incarceration.
Though Talia still holds a grudge against Oliver for killing her father, the two worked together to take down the evil Dr. Parker, who has been conducting unethical tests on inmates in the facility's Level 2. Right when it looked like freedom was in their reach, Oliver decided to stay behind. He realized if he were to go on the run, it would mark him a fugitive and eliminate any chance at a reunion with Felicity and William. Of course, Talia then used her newfound freedom to assassinate Dr. Parker.
Airing Mondays at 8 pm ET/PT on The CW, Arrow stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Emily Bett Rickards as Felicity Smoak, Rick Gonzalez as Wild Dog, Echo Kellum as Mr. Terrific, Juliana Harkavy as Black Canary, Colton Haynes as Arsenal, Kirk Acevedo as Diaz and Katie Cassidy as Black Siren.