Flash Supergirl crossover
The Flash and Supergirl crossover is happening at CBS The CW/ CBS

Supergirl and The Flash crossover is happening, and fans finally get a first glimpse of the special episode, which is being filmed right now in Los Angeles. Grant Gustin has shared a behind-the-set image featuring the Speedster Barry Allen and Melissa Benoist's Kara Danvers.

Gustin captioned the picture, "Those two emblems look pretty good together". Gustin's character will visit Supergirl's National City in the 28 March episode titled Worlds Finest.

Those two emblems look pretty good together... @melissabenoist

A photo posted by Grant Gustin (@grantgust) on

The actor also shared a picture of his "fancy" chair at CBS's show set. He wrote, "Hey Flash producers... I've already got a fancier chair on Supergirl than I've got on Flash. Just saying..."

Hey Flash producers... I've already got a fancier chair on Supergirl than I've got on Flash. Just saying...

A photo posted by Grant Gustin (@grantgust) on

The Star is all excited to meet Supergirl, given that she popped up in a small cameo in The Flash season 2's episode, titled, Welcome To Earth 2. When Barry, Cisco, and Harrison Wells travelled through the Speed Cannon, fans got a glimpse of Kara aka Supergirl.

Previously, The Flash and Supergirl executive producers Greg Berlanti and Andrew Kreisberg said in a statement: "We are so incredibly excited to announce something that we have dreamed of happening since we starting making Supergirl — The Flash and Supergirl are teaming up!"

"We want to thank Grant Gustin for making the time to come visit (on top of his already immense workload) and all of the folks at CBS, The CW, Warner Bros. and DC for working this out. And finally thanks to the fans and journalists who have kept asking for this to happen. It is our pleasure and hope to create an episode worthy of everyone's enthusiasm and support," they said.