'The Flash' Echoes a Key Line from 'Supergirl'

Events and Easter eggs throughout the Arrowverse shows on The CW remind viewers that the heroes live in one big shared universe. However, in addition to the big tells there are other little nods from one show to another that you might have missed.

In tonight's season four premiere of The Flash Cisco has one of those nods, this time in the form of a line calling back to last night's third season premiere of Supergirl.

Spoilers for The Flash's season four premiere, 'The Flash Reborn', below.

Near the end of the episode, and after Barry returns from taking down the Samuroid that had flown off with Iris, Team Flash is celebrating both the defeat of the android villain and Barry's return to them from not only his six months in the Speed Force, but the scrambled state he was in as well. Iris, who had been running things in Barry's absence, thanks Cisco for having the faith that they could bring Barry home that she herself had been sorely lacking earlier in the episode. Cisco's response?

"See you tomorrow, boss."

Last night in Supergirl's premiere, right at the end Kara texts the same message to Lena Luthor as, earlier in the episode, Lena bought CatCo to prevent Morgan Edge from doing it and using the media empire for his own nefarious gain. It signalled Kara's return to her humanity and her friends much like Cisco's line signalled the return of Barry and Team Flash. Also, while Kara texted instead of speaking the line, it's a nice connection between the two shows and subtly reminds fans that despite Supergirl living on Earth-38, she's still very much a part of the Flash's world.

While this part of The Flash's fourth season might not be the most fascinating -- the mystery of who's behind that Samuroid is pretty compelling stuff -- it's nice to see the shows staying connected ahead of the four-part crossover later this fall. For now, though, fans will just have to stay tuned with The Flash's new season, which airs Tuesdays at 8/7c, on The CW.