The Flash Photos from "Cause and Effect"

at .

Team Flash has a new ally in their quest to stop Savitar from killing Iris on The Flash Season 3 Episode 21 "Cause and Effect."

Still reeling from learning the truth about his future self, Barry's hoping Tracy can stop him for good. H.R.'s by the physicist's side as she begins to test her theories.

In the photos below, another familiar face pops up in the lab as well. But what does she intend to do there?

Scroll through the photos, and share your thoughts with us! Do you think Tracy will find the answer? What does Killer Frost want from her former team?

Remember, you can watch The Flash online anytime!

1. WestAllen's Awkward Chat - The Flash Season 3 Episode 21

Now that Barry knows he's the one trying to kill Iris, there might be some extra tension in their relationship. Of course we still don't know why Future Barry's hellbent on murdering his true love.

2. Lost in Thought - The Flash Season 3 Episode 21

Poor Iris. For months, she's been grappling with the fact that her number might be up in May. Now she knows the person out to get her is Barry. We can't blame her for looking a little sad.

3. Father Daughter Moments - The Flash Season 3 Episode 21

Joe's not going to let anything happen to his daughter. But how does he stop a version of his son from killing her? That's a pretty complicated family dynamic.

4. H.R. Likes Science - The Flash Season 3 Episode 21

Is H.R. finally embracing the Harrison Wells roots? Is he ready to learn physics? We're thinking the more likely scenario is he wants to get to know Tracy better. #Traison? #Brells?

5. Demonstration Time - The Flash Season 3 Episode 21

We know Tracy eventually comes up with the solution to trap Savitar in the Speed Force. But we also know he finds a way out. Could she be preparing a more permanent solution?

6. Joe and His Superhero Sons - The Flash Season 3 Episode 21

Waiting around is the hardest part for anyone. Barry and Wally are both suited up. Are they on a mission with Joe working on a new case? Or have they found a way to save Iris?

7. Exchanging Glances - The Flash Season 3 Episode 21

Barry and Wally have come a long way as teammates since Wally first donned the costume. Now all they have to do is look at each other to know what the other is thinking.

8. Ready to Flash? - The Flash Season 3 Episode 21

It's not often we see Barry idling in his Flash costume. This might have something to do with Tracy being in the lab. How long until she's let in on his not-so-secret identity?

9. Team Flash Represent! - The Flash Season 3 Episode 21

Team Flash gathers at STAR labs to hear what Tracy has to say. With Iris' life on the line, and future Barry behind Savitar, time is of the essence.

10. Hard at Work - The Flash Season 3 Episode 21

We hope Tracy's not planning another fire. Now that she has someone to believe in her, the future Nobel Prize winner can get to work on finding a solution to the Savitar problem.

11. Cheerleader Wells - The Flash Season 3 Episode 21

H.R. has proven himself to be a great coach when someone needs a pep talk. He's doing what he can to make sure Tracy feels at home in the lab. Plus, we're sensing a little crush.

12. Tense Teamwork - The Flash Season 3 Episode 21

What's making Julian and the others so tense? Is it what they're seeing on the monitors? Or is it the fact that Killer Frost is casually lurking in the background?

13. Saving the Day - The Flash Season 3 Episode 21

We're worried about Cisco. He's having a hard time with the Killer Frost situation. Now, whatever he sees on the screen is upsetting him. Will he ever catch a break?

14. Killer Frost Drops By - The Flash Season 3 Episode 21

Has Caitlin come to her senses? Or does Killer Frost have another reason for popping into STAR labs? We're guessing Wally and Julian have as many questions as we do.

15. Surrendering? - The Flash Season 3 Episode 21

Is Killer Frost ready to turn herself in? That sounds like something Caitlin Snow would do. But this could be a trap. Maybe Savitar's sent her there for information.

16. Wally Worries - The Flash Season 3 Episode 21

It can't be easy for Wally to know there's not much he can do to save Iris. Even at his fastest, he wasn't fast enough. But we don't see Kid Flash backing down any time soon.

17. Cisco Side Eye - The Flash Season 3 Episode 21

What's better: Cisco's flawless side eye or his hair game? We're kidding. We don't expect anyone to choose. Cisco's too great at everything for that. But can he stop Savitar?

18. Surprise Entrance - The Flash Season 3 Episode 21

Wally, Julian, and Cisco look like they're just arriving at the lab. They probably didn't expect to find a certain potential villain waiting for them at work.

19. I'm Back! - The Flash Season 3 Episode 21

Killer Frost has a proposition for Team Flash. But is it another trick? Or does she have a way to allow them to coexist without killing each other?

Wait! There's more! Just click "Next" below:

Next
Show Comments
Show:
The Flash
Episode:
The Flash Season 3 Episode 21: "Cause and Effect"
Related Photos:
The Flash Slideshows
Related Post:
Created by:
Published: