The Flash star Grant Gustin has released the first photo of himself in costume alongside Supergirl's Melissa Benoist, on the set of the Supergirl episode "Worlds Finest."

Following on the heels of a big ratings gain for Supergirl this week and then the highest-rated episode of The Flash in more than a year, Gustin headed from Vancouver to Los Angeles earlier today to start filming the crossover episode fans have demanded more or less since the moment the pair appeared in a photo shoot with executive producer Greg Berlanti before Supergirl's season even started this fall.

Those two emblems look pretty good together... @melissabenoist A photo posted by Grant Gustin (@grantgust) on Feb 10, 2016 at 2:07pm PST

Details remain under wraps regarding the crossover, but following a cameo by Benoist's Supergirl in The Bleed between Earth-1 and Earth-2 on last night's episode of The Flash, it's generally assumed that the story will involve Barry making his way over from another Earth to help Team Supergirl. If it's anything like the crossovers between Arrow and The Flash, expect some big story movement for Supergirl. It tends to happen that when the crossovers take place, that Team Flash will leave Team Arrow with a parting gift (like a new costume) that turns out to be pretty important.