Up Up and Away and Hello Speedsters and DC Comics Fans , Here is my review of The Supergirl / The Flash Crossover episode Supergirl Season 1 Episode 18 Worlds Finest 1st as always a description of the episode : The Flash comes from an alternative universe and aids Kara in her battle against Silver Banshee and Livewire in exchange for her help getting home. Now on to my review of The episode Warning Full Spoilers To Follow , Wow this episode was super amazing!!! It was amazing , awesome , action packed and emotional also it ended on a cliffhanger. Oh the feels in this crossover episode. Supergirl and The Flash had their hands full with Silver Banshee and Livewire. Now this is a crossover episode with CBS’s Supergirl and The CW’s The Flash. The episode begins with Silver Banshee with her new powers screaming and pulling Kara out of the window of Catco that is until a yellow blur comes in and that is The Flash Barry Allen who is running so fast he does not know which earth he is on mention to Supergirl all the heroes and bad guys from his earth but she did not understand that is until he tells Kara he got lost and needs help getting back to Earth One. Silver Banshee and Livewire they form a plot to take down Supergirl and The Flash by kidnapping Cat Grant now in their 1st fight at a warehouse Kara loses for a bit here Super Hearing and is still down that National City she let down but then Barry tells Kara don’t worry the same thing happened to me referring to the time Barry went bad for a shot time vs Oliver before The Arrow cured The Flash. The final fight between Silver Banshee and Livewire vs Supergirl and The Flash was amazing outside in front of Catco and they have the upper hand and almost kill Supergirl that is until not Barry but The National City Fire Department saves Supergirl and National City earns her trust back. The other stuff in the episode like James , Winn and Lucy’s interactions with Barry Allen and also The Flash / Supergirl race was amazing too. And then the big cliffhanger when Kara kisses James she thinks he forgave her but Non and the mystery of The Myriad comes back and Non is starting an army but that is for the next episode in 2 weeks. Melissa Benoist and Grant Gustin where so good in this episode they did a great job as Supergirl and The Flash and The Special Effects , Music and Production Design where just amazing. I liked Blake Neely’s uses of Supergirl’s and The Flash’s themes in this episode. Overall I give The Supergirl / The Flash Crossover Worlds Finest a 10/10 a super amazing awesome episode. Can’t wait for the next episode of Supergirl in 2 weeks titled Myriad and the next episode of The Flash tommrow night titled Flash Back.