Melissa Benoist as Supergirl, Grant Gustin as Barry Allen
Kara (Melissa Benoist) may use her inter-dimensional extrapolator again for the previously announced “The Flash” and “Supergirl” musical crossover that is set to air sometime in spring 2017. The CW

Fans of CW’s DC TV universe may have to wait until spring 2017 to see Kara use her inter-dimensional extrapolator again.

At the end of last night’s “Legends of Tomorrow” “Invasion!” episode, Cisco (Carlos Valdes) gave Kara (Melisa Benoist) an inter-dimensional extrapolator that allows her to travel between Earth-38 and Earth-1 with ease. The portable breach-opener also comes with communication functionality that allows her to contact the team on Earth 1 at any given time if she needs help. Kara used the device for the first time when she returned to her Earth during the final moments of the crossover event, and it seems that it will take quite some before she uses the gadget again.

“They’ve gotten to the point where we wanted to make [future crossovers] a little bit easier,” “Supergirl” executive producer Andrew Kreisberg said (via IGN) of why Kara’s inter-dimensional extrapolator is an important storytelling device. “The next time we do it, it means it doesn't necessarily have to be because Oliver (Stephen Amell) and Barry (Grant Gustin) need Kara; it could be because Kara needs them. … [The portable breach-opener] just gives us another way to come at a story.”

While Kreisberg didn’t mention anything about Kara using the device again, it does make sense if the Girl of Steel uses it for the previously announced “The Flash” and “Supergirl” musical crossover that is set to air sometime in spring 2017.

During the Entertainment Weekly PopFest in October, Greg Berlanti admitted that he and his fellow executive producers “have just started” to think about the musical crossover because they had become really busy working on the “Invasion!” crossover event.

Although plot details are very limited, Berlanti said in an interview with IndieWire in September that the musical crossover may feature some original songs.

“We’ll have to start talking about clearing music,” Berlanti said at the time. “I have a few ideas for tone and style in my head but we’re just starting to talk about what that can be. I do want to try and get an original piece of music written. As we make a deal on that we’ll probably make some announcements on the original songs.”

Are you excited for “The Flash” and “Supergirl” musical crossover? Sound off in the comments below!