Ep 7. Killer Frost

After deciding to track down a potential new ally, Barry (The Flash) sets out to learn everything he can about Dr. Alchemy. His investigation leads him to Caitlin Snow, who may be unwilling to aid his cause. When Caitlin is contacted by an old friend to help him sabotage S.T.A.R. Labs' research, she's hesitant but decides to help. As Barry's team tries to stop her and her friend, Caitlin's abilities begin to show themselves as Killer Frost emerges once again.

The episode begins with Barry and Iris on a date when Barry suddenly disappears, leaving Iris at the restaurant. He has gone to the police station to find Julian, who he believes is working with Dr. Alchemy. Barry's theory is proven correct when Julian finds a husk, or empty cocoon, on his desk. His reaction to the husk and his knowledge of its significance convince Barry that Julian is connected to Dr. Alchemy.

In hopes of finding a new ally, Barry visits Caitlin Snow, whom he knows is connected to Dr. Alchemy. Caitlin is hesitant to help, but Barry convinces her to reveal everything she knows about the villain. When she mentions her fear of her powers and how she won't want to be like her Earth-2 counterpart, Killer Frost, Barry assures Caitlin that he will always be there to help her, no matter what.

Meanwhile, Caitlin is contacted by a former colleague, who needs her help to sabotage a research team at S.T.A.R. Labs. Although Caitlin is hesitant, she eventually agrees to help, as she believes she will be able to fix any damage that she causes. However, things take a dangerous turn when her colleague reveals that he has captured Harry Wells's daughter, Jesse, and will only release her if they help him complete the mission.

Back at S.T.A.R. Labs, the team discovers that Caitlin has hacked into the system to create an embedded error in the S.T.A.R. Labs particle accelerator. At the same time, Cisco is struggling to fix Gypsy's breach device, which will allow him to track down Julian and Dr. Alchemy. When Caitlin is confronted about her actions, Killer Frost emerges, freezing the room in a wave of ice.

As the team tries to figure out how to stop Caitlin, she undergoes a transformation into Killer Frost, giving Cisco and Gypsy a taste of what's to come if they're not careful. Meanwhile, Barry tries to reason with Caitlin, telling her that she can fight her powers, but to no avail. Killer Frost is determined to protect Caitlin from anyone who will try to control her powers.

In the end, the team is forced to confront Caitlin and Killer Frost. Their actions cause a great deal of destruction and can have far-reaching consequences. Barry is left with a difficult choice, as he is forced to choose between his friend and his duty as a hero. The episode ends on a cliffhanger, leaving fans wondering what will become of the beloved character.

Overall, "Killer Frost" is a thrilling and action-packed episode that showcases the strength of the show's characters and their relationships. The emergence of Killer Frost and the toll it takes on Caitlin only adds more emotional depth to the storyline. This episode is a must-watch for anyone who is a fan of the Flash and superhero dramas.