Kara Danvers may need to tap in a certain Scarlet Speedster as Silver Banshee's Supergirl reign of terror spills into "Worlds Finest."

'The Flash' Season 2: 'Supergirl' Crossover Is Official, DC Sets Date For Barry's National City Adventure

The Flash will cross with DC's kryptonian series in episode 18, but the reason behind the team up has yet to be announced. A new set photo, however, may provide a little insight into Barry's (Grant Gustin) trip to Central City.

Featuring Grant Gustin in the foreground, this candid pic from the set of Supergirl gives fans us our first look at Siobhan Smythe (Italia Ricci) in her Silver Banshee get up. See image here.

'The Flash' Season 2: What's Next For Hunter Zolomon? Danielle Panabaker & EP Tease Return

While we've seen Sibohan as a regular, everyday CatCo employee in stills for "Truth, Justice and the American Way," but the snap from Imgur is the first decent look we've seen of her alter ego. It appears Kara (Melissa Benoist) and Sibohan's workplace rivalry will spiral into something much more devastating.

Even though we might have pinned down the crossover's villain, there are still so many unanswered questions. The Flash has yet to acknowledge the existence of aliens, let alone Supergirl. It looks like we'll have to wait just a little bit longer to find out exactly how Barry will handle his little National City field trip.

Supergirl airs Mondays at 8 p.m. ET on CBS. The Flash airs Tuesdays at 8 p.m. ET on The CW.