Rumors that a crossover between FOX's "Gotham" and CW's "Supergirl" have surfaced after CW posted the "Teaming Up" trailer for season 2 of "Supergirl". At the end of the trailer, the line "We're moving back to Gotham" is heard. Although some think it was just a throwaway line, fans are speculating it's a sign for a crossover event in the future between the two series. Meanwhile, Gotham just released a trailer and it shows the Mad Hatter taunting Gordon saying "We both know you can't kill me..."

Executive Producer of "Supergirl", Ali Adler, was interviewed about the rumor and said "We have this beautiful history with DC, and I like that we get to borrow from this amazing, wonderful canon that we have," Unfortunately, Adler said the "Gotham reference" doesn't mean anything and clears that the series will not have a crossover with "Gotham"

Adler also explained "We have our hands full with the crossover we're shooting right now," referring to the confirmed four-way crossover of "The Flash", "Legends of Tomorrow", "Arrow" and "Supergirl". "I think people will be satisfied with how much crossover they're getting this season." she added. Moreover, "Gotham" is set in a timeline from the past while the rest of CW's DC Comic television series are in the present.

However, David Mazouz from "Gotham" said a crossover from the two networks is not impossible at all. Especially now that "The Flash" can do time traveling, he added. "The whole problem before was that 'Gotham' is set in the past while the other shows ... are set in the present. But, now that there's time travel introduced to the CW-Verse, I don't see why not. But it's not my call."

In other news, "Gotham" season 3 centers on the comeback of the infamous Court of the Owls and Jim Gordon has no choice but to take matters into his own hands. The season will also feature Poison Ivy and Jervis Tetch also known as the Mad Hatter.