After a whole lot of will-they-won't-they, Greg Berlanti finally revealed earlier this month that Supergirl and The Flash will be crossing over. Almost immediately after the announcement, we caught a glimpse of Supergirl in the Speed Tunnel during last week's Flash episode: 'Welcome To Earth 2'. Grant Gustin has also been posting Instagram photos of himself with Melissa Benoist, as he is currently in LA filming with them.
Gustin also shared a photo of the cover page of his episode's script. Titled 'World's Finest', we don't have any further details about the plot, but we do know that it will be episode 18.
Now, we have got our first hint at what might bring the Scarlet Speedster together with Supergirl, with this behind-the-scenes photo showing Gustin, Benoist, and a well-known villain.
Grant Gustin is obviously the focus of the shot, as he meanders about set half-Flash-half-Grant, and we can see Benoist in her costume behind him (some of her, anyway). Behind that, however, is the really interesting part. Sitting down in full makeup, we can spot Italia Ricci as Siobhan Smythe, a.k.a. Silver Banshee!
Ricci had previously been confirmed as Siobhan Smythe, a new assistant at CatCo who will make her debut next week in 'Truth, Justice and the American Way'. Siobhan will be trying to one-up Kara at work, while she is dealing with other threats as Supergirl, and it is currently unknown whether or not she will be appearing as Silver Banshee as well as Siobhan in this episode.
If she does, we can assume that Kara doesn't manage to take her down just yet, as this new photo shows that Silver Banshee will be up against the combined forces of Supergirl and Flash. Perhaps Silver Banshee will be a villain with a multi-episode story arc, which would balance out some of the one-shot bad guys nicely.
In the comics, Silver Banshee is often up against Supergirl and Superman as she searches for an occult book the belonged to her father. She has befriended Kara in the past, and the two have battled together against her father, the Black Banshee. Her powers include the ability to understand any language, and a death-shriek that she can use to kill anyone she desires (as long as she knows their true identity).