“I don’t know which characters, but there are going to be crossovers for sure between the two shows," Gustin said when quizzed about an Arrow crossover story. "I don’t know who it’s going to be, but yes, that’s gonna happen.”
Shortly before that, though, he was asked about the integration of the DC Universe into The Flash -- something that Arrow has had a great deal of success with.
"There's probably Easter eggs that I'm not even catching because Andrew Kreisberg and Greg Berlanti are so good at that," he said. "There's going to be so many Easter eggs for the fans; it's so fun."