'Supergirl' S01E18: "World's Finest" Melissa Benoist, Calista Flockhart Premiere Recap!

CBS continues with the  premiere of their DC Comics' heroine, Supergirl. In episode 18, what happens when Kara Danvers (Melissa Benoist), Alex Danvers (Chyler Leigh), and Cat Grant (Calista Flockhart) meet Barry Allen aka The Flash (Grant Gustin) in World's Finest?

As Silver Banshee (Italia Ricci) is being tested in a lab, Supergirl wonders if she will ever win the trust of the public back. Though Winn (Jeremy Jordan) is unable to explain what happened to her, Silver Banshee finds herself possessed. Banshee spies on Livewire (Brit Morgan) and Lucy (Jenna Dewan)'s conversation. 

Cat tries to give advice about James (Mehcad Brooks) to Kara; try less, shine more. Finally taken over, Silver Banshee storms not the office and unleashes her power. After being thrown out the window, the Flash rips through a portal and saves her. 

Out in the mountains, Barry removes his mask and realizes he is on the wrong Earth. In her office, Barry tries to explain the multiverse to Winn and James. Barry then brings everyone ice cream to show his super-speed. Barry is stuck in National City until he can find his way back. Winn notices a hint of jealousy in James. 

Cat knows there is a new superhero in town and names him "The Blur." She notices James is also jealous of Barry. Silver Banshee meets her aunt for help; the Banshee is calling her. The curse can only be lifted unless she gets back the person who wronged her. The Banshee allows Livewire to escape.

Kara realizes she needs Barry's help against Livewire. The two superheroes shake hands as partners. The Flash shows up at the DEO and works at their crime lab. Banshee and Livewire meet at an abandoned hideout to discuss how to kill Cat, Supergirl, and Kara,

As Lucy and James wonder if their relationship was ever going to work out, Barry has  found out the hideout. The Flash hits Livewire with lightning but she absorbs it. Silver Banshee's scream unfortunately make Supergirl's ears bleed. Knowing they're outmatched, the two superheroes make a run for it. 

Barry and Kara share a tender moment on the rooftop; you need to slow down. Time fixes things on its own. Livelier and Silver Banshee show up at the office, taking Cat hostage. Winn tries to get in the way, but Silver Banshee hits him. The Flash and Supergirl race together to fight their opponents in a rematch.

As the super-villains attack the park, Supergirl's ear buds protect her. The scarlet speedster takes on Livewire as Supergirl fights Silver Banshee. Supergirl falls after taking a hit from Livewire. The crowd then stands in front of Supergirl as the firefighters douse Livewire with water. Silver Banshee is taken down after Livewire electrocutes her.

Cat already knew Barry is The Flash because he's too nice. The Flash and Supergirl will have to race each other, in order for him to return home. They will miss each other. She says goodbye after the scarlet speedster returns home.

Just when Kara and James kiss, he finds himself under a trance, along with everyone else.  The alien invasion has begin. 

Readers, what did you think of World's Finest?