Grant Gustin Joins 'Supergirl' in 'The Flash' Crossover Episode Poster

The Flash‘s Grant Gustin and Supergirl‘s Melissa Benoist join forces and recreate a classic comic book cover in a new poster for their crossover episode.

The 26-year-old actor is set to guest star as The Flash on an upcoming episode of Supergirl, visiting her realm from an alternate universe.

PHOTOS: Check out the latest pics of Grant Gustin

In the episode, The Flash helps Supergirl battle Siobhan (played by Italia Ricci), aka Silver Banshee, and Livewire in exchange for her help in finding a way to return him home.

“Check out this new comic cover that @melissabenoist and I recreated. I do believe the recreation is from a Superman/Flash cover, but Supergirl makes everything look better. Don’t miss the crossover on March 28! @supergirlofficial @cwtheflash,” Grant wrote on his Instagram.

Grant guest stars as The Flash on Supergirl airing March 28th on CBS.