S01E18 Worlds Finest
Acção, Aventura, Drama
When former CatCo employee, Siobahn Smythe upset at how her life is going discovers something odd about herself. She then goes to a relative who tells her of their family's secret--that they were cursed by a banshee. Which comes out when one of them is angered. And she needs to destroy the object of their anger, in this case Cat, Kara and Supergirl. She tries to kill Kara but she is saved by a visitor from another universe, The Flash who was attempting to cross into another universe and ended up in hers. She reveals herself as Supergirl. they try to figure out how to get him back to his universe. Siobahn who now calls herself Silver Banshee makes another attempt but is captured by Supergirl. And she's taken to the DEO. and while there she meets Live wire. And later she escapes and frees Livewire and together they team up to go after Supergirl.