Alex tries to convince Kara to forgive Hank and come back to the DEO, but Kara doesn't think she can.

Cat receives a thumb drive about a website of powerful adulterers. Cat is not interested in doing anything with it, but Lucy believes the public deserves to know the truth. 

James asks Kara about telling Lucy her secret again, but Kara says no.

The hacker who sent the drive hacks into all the traffic lights in the city, causing accidents. 

Cat wants to find the hacker and end her terrorism. 

The hacker, Indigo, comes through Winn's computer into Kara's apartment and attacks them.

Non approaches Indigo, they know each other. 

Winn learns Siobhan's father is one of the cheaters. 

Alex comes to ask Winn to help at the DEO.

James shows Kara Superman's Fortress of Solitude and they learn about Indigo.

James forgets a date with Lucy. Kara tries to help, but makes it worse. 

Lucy discovers that Indigo had a specific target, a general she plans to use to launch a nuclear attack.

Kara chases after the missile. She calls Hank for help and they manage to stop it. 

Winn hits Indigo with malware. Indigo tells Kara that she's the reason she made it to Earth.

Siobhan kisses Winn.

Kara gives James permission to tell Lucy her secret, but Lucy breaks up with him before he gets the chance. 

Kara returns to the DEO. Alex admits that she's the one who killed Astra and Kara forgives her with a hug. 

Non brings Indigo back.