Worlds Finest

"Worlds Finest" -- Kara gains a new ally when the lightning-fast superhero The Flash suddenly appears from an alternate universe and helps Kara battle Siobhan, aka Silver Banshee, and Livewire (Brit Morgan, pictured) in exchange for her help in finding a way to return him home, on SUPERGIRL, Monday, March 28 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Photo: Robert Voets/Warner Bros. Entertainment Inc. © 2016 WBEI. All rights reserved.