STAR Labs detects Fractal Energy in Central City, AKA Eva. Chester wakes up Barry, who was in a cryo pod preserving his speed.

Barry chases after Eva, even though he only has one percent of his speed left. Eva gets away and confronts Black Hole members.

She kills Sam Scudder, AKA Mirror Master, in front of his girlfriend Rosa Dillion, AKA Top. They were both working for Black Hole.

Iris, still trapped in the Mirrorverse, hallucinates a date with Barry.

The world believes Sue killed Carver, so she and Ralph are in hiding. And Caitlin and Cisco are still gone, too.

To complete the Artificial Speed Force, they need a fuel source to power the fusion sphere.

Nash is visited by the other Wells. They tell him that there are multiversal particles in him as a result of the Crisis that can power the fusion sphere.

But to do so, Nash would become the organic receptor for the Artificial Speed Force, resulting in his death. Nash rejects this idea.

Cecile gets Rosa to tell her that she was working with Eva and sold out Scudder to her.

Nash figures out that Allegra can push the multiversal particles out of him and into the fusion sphere.

Their plan goes awry, though, and all of the Wells' brainwaves enter Barry. Barry wakes up as Sherloque Wells.

Barry continues to switch between Wells'.

Iris is confronted by different versions of herself from past seasons, a product of her broken mind. 

Barry faints. Chester uses mobile Gideon to diagnose him. The infusion of the multiversal particles is causing his cerebral cortex to overload. The only thing keeping him alive is his speed healing.

Iris realizes that Eva is the one who is messing with her by taunting her with different versions of herself.

Cecile uses her powers to get Rosa to tell her what she and Eva are planning.

There's a supersonic jet about to leave a secret Black Hole site that is loaded with all of Carver's remaining tech and a bomb.

Allegra pushes the particles out of Barry and into Nash.

Nash acts as the organic receptor, giving Barry back his speed. Nash and all other Wells die.

Barry stops the jet and the bomb.

Iris tries sending a message to Kamille and Singh. The laptop screen ripples.

Eva opens up one of Carver's files, labeled "For Eva." It's a video that shows the real Eva dying after the explosion. The Eva we see now is the mirror duplicate.