We open in a slow-motion moment with a voice over of Nora telling the audience all she wanted to do was save her father and get to know her parents. We then watch Elongated Man absorb a cold gun blast and fall.
At Star Lab's they try and figure out how to fix Ralph and locate Cicada II. Cisco gets a text from Kamilla and is stressed he hasn't come clean about being Vibe yet.
At CCPD, Cecile and Joe tell the captain that metas are safe, but Cicada is still free and people are still in danger. Barry finds a shard of wood on the ground and thinks it might be a clue to finding Cicada.
Back at Grace's house, she continues to hallucinate Orlin, who is pushing her to destroy all meta's as soon as she can.
At Star Labs Cisco takes the piece of wood to analyze and figure out where Grace may be. Sherloque reveals he understands why Ralph jumped in front of the gun blast--so the dagger wouldn't disappear and allow Thawne to escape his imprisonment.
We jump to the future where Thawne is about to be executed.
In the present, the Team realizes Thawne's real motives. Nora grapples with the fact she fell for his lies. They debate whether to stop Thawne or stop Cicada. Barry votes to save the metas. Caitlin tells Cisco to go see Kamilla.
At Jitters, Cisco meets up with Kamilla. Cisco tells her the truth about what he does and who he is by demonstrating his powers. He goes to leave, thinking she can't forgive him, but she ends up completely understanding why he kept his secret.
At Star Labs, Barry gives a pep talk to Nora about accepting the fact she messed up with Thawne and moving forward.
Caitlin continues to try and figure out how to fix Ralph but she can't understand how to get his cells back to normal. Sherloque realizes they can use muscle memory to help him by waking him up--with a blast from Vibe.
Cisco blasts Ralph and he's successful with waking him. There is a alert that a location for Cicada is traceable, but the area is too wide. Nora says she has her own plan that can stop both Cicada and Thawne.
The Team thinks Cecile can be used as a warning system for Cicada as they try and track her down. They then decide to get Cicada to take the cure before taking her dagger and getting rid of Thawne.
The team finds Cicada's house in the woods. She goes to attack but Joe throws a breach and they lock her in at Star Labs. Nora then tries to telepathically tap into Grace and push the cure on her.
Inside Grace's mind, Nora tries to remind child Grace that she's a meta just like her uncle was. Meta Orlin and Human Orlin manifest in an angel/devil scenario debating over if Grace should take the cure or kill all metahumans.
Grace agrees to take the cure, and child Grace wakes up. Just as child Grace is ingesting it, adult Grace comes in and attacks the entirety of Team Flash. They realize the dagger itself carries enough dark matter to keep Cicada a meta.
Grace takes Nora's powers and goes to stab her, but Barry blasts the dagger with a cold gun just in time. The dagger disappears, and so does Grace.
Things Flash to Thawne, who is able to escape his death, now that the dagger no longer exists. The prison guards try to kill Thawne but he murders them within seconds.
The scene then reverses to right as Thawne escapes, and XS and The Flash show up. The Flash explains how Thawnes plan was for Nora to go back to time and change who Cicada was, so she was no longer unstoppable, like in the original timeline.
Thawne confesses and claims to be the only speedster who knows how to manipulate the timeline to get what he wants. Thawne then speeds away and The Flash and XS chase after him.
Thawne stops in his tracks to tell Nora she will never be able to save her father, he will always vanish. The rest of Team Flash then breeches in and knocks Thawne down.
Thawne goes to attack the team but Vibe breeches him and Xs/The Flash run towards him at full speed, knocking him down. Nora taps into the negative speed force and goes to kill Thawne but Barry and Iris stop her.
XS begins to disappear, and Thawne reveals a new timeline has begun and now Nora's existence has been altered. Thawne tells Barry the only way to save her is to take her back into the negative speed force.
XS starts to tap into it but then turns back. If she goes back into the negative speed force, she will become evil forever--and that can't be her legacy.
Nora decides to own her mistake and the West-Allen's hug until Nora disappears completely.
The Team heads back to Star Labs and reminisces about how much Nora helped them, and kept them from losing everything. Sherloque then decides to leave, now that the mystery has been solved.
Cecile and Joe get an alert from Sing to get to CCPD. Iris asks to be alone. She sees Nora's journal that's been left behind.
Cisco tells Caitlin he no longer wants to be Vibe. Caitlin gives Cisco the cure.
At CCPD, SIng thanks Joe for everything he did regarding Cicada. Sing then reveals he's been promoted to the Chief of Police and asks Joe if he will take the job as Captain. Sing then reveals he knows Barry is Flash.
Iris mourns Nora at the lab and Barry joins her. As they look through Nora's journal, they find a chip that ends up being a video of Nora saying goodbye.
The last scene shows Gideon alerting the Team to a time influx: The article on Barry's disappearance during crisis shifts to 2019.