Due to similar plot lines to the Paris attacks, Supergirl replaced episode 104 with 105. Episode 104 will premiere next week instead. On this week’s Supergirl, Alex and Kara deal with family issues on Thanksgiving, and Kara teams up with Cat to fight an electrifying new villain.

Dr. Danvers is in town for Thanksgiving. Alex is worried that she’ll come down hard on her for letting Kara become Supergirl, but things start off fine.

Leslie Willis, a shock-jock, puts down Supergirl on the radio. Cat is upset. She tells Leslie that Supergirl is off limits because she’s trying to cultivate a relationship between Supergirl and Cat Co. Cat transfers Leslie to the traffic helicopter and takes away her show.

Kara invites Winn to her family Thanksgiving because she finds out he has nowhere to go.

Kara goes to pick up food and sees James sitting at a table alone. She asks him to Thanksgiving dinner, but he’s going out of town with Lucy.

Alex tells Kara that Dr. Danvers has always come down hard on her about taking care of Kara. Kara tells her to come out about being a DEO agent so she’ll know she’s protecting her.

The traffic chopper gets hit in a lightning storm and starts to crash. The pilot falls from the helicopter. Kara catches him and puts him on the ground, then tries to pull Leslie from it. A bolt of lightning goes through Supergirl and hits Leslie.

Cat and Kara visit Leslie’s hospital room while she sleeps. Cat tells Kara it isn’t Supergirl’s fault that Leslie is in the hospital, it’s her own. After Kara leaves, Cat tells Leslie that she’s tougher than a bolt of lightning. When she leaves, the lights go haywire and Leslie’s eyes glow electric blue.

Dr. Danvers confronts Alex about letting Kara become Supergirl. Alex leaves in a fury.

As Leslie leaves the hospital, a man tries to attack her, but she shocks him with lightning, laughs at the rush and disappears.

At Thanksgiving dinner, Dr. Danvers asks Kara to use her heat vision on the turkey, then makes a comment about how much wine Alex is drinking. Kara tries to get everyone to say what they’re feeling, but then gets a call from James checking up on her.

Alex tells her mom about the DEO. Dr. Danvers yells at her, and Alex and Winn both leave. Kara confronts her mom about being hard on Alex, then leaves for work when she gets a text from Cat.

Flashback to the girls sneaking out of their bedroom and flying. When they get back, their parents are waiting for them. Their dad yells at them for using her powers because they could have been seen. There’s a knock on the door and their parents send the girls upstairs. Hank is at the door.

Cat tells Kara none of her electronics are working. Kara says they need Winn. Cat doesn’t know who he is. The power goes out completely and Leslie appears on the televisions in Cat’s office. She says her name is Livewire. She appears in front of the screens and shoots lightning at Cat and Kara. Cat sends Kara to get security.

Livewire moves through bolts of lightning. Supergirl tries to fight her off with her heat vision, but Livewire just absorbs the energy. Cat tries to take an elevator, but the power goes crazy and it starts to fall. Kara catches it and lets Cat out.

The city is having power outages. Hank tells Kara that her body was element X that transformed Leslie into Livewire. He says he might be able to adapt a trap used to capture aliens who are just sentient energy into something that can trap Livewire.

Cat tells Kara she can go home. Kara says she’s not eager to go back to her family because her foster mother and sister are fighting. Cat asks about her family and Kara tells her that her parents died in a fire when she was 13. Cat admits that she pushes herself and others too hard because her mother is never satisfied with her. Cat says she helped create Livewire by encouraging her to be awful. She asks the FBI to get her in touch with Supergirl.

Alex checks on her mother in the blackout. Dr. Danvers apologizes for being hard on her. Alex apologizes for keeping things from her. Alex leaves to help the DEO.

Cat tells Supergirl she can draw Livewire out if they partner together. Hank gives Kara a trap that will hold Livewire in her energy form.

Cat broadcasts for Livewire to meet her. Livewire attacks her and Supergirl fights, trying to get her near the trap. Livewire blasts it and tries to kill Supergirl, but Cat distracts her long enough for Kara to attack her with the water main which stops her.

Kara brings Winn a complete helping of Thanksgiving dinner in Tupperware to apologize for her crazy family. He tells her that his dad is in prison, so his family doesn’t celebrate holidays. He says he was grateful to be included with hers. He says he’s grateful for her and gives her a kiss on the cheek.

Cat tells Kara to skip the humiliating celebrity stories that morning. Instead she wants to do a photo essay of volunteers for charitable organizations. She also tells Kara that she’d like to learn more about her.

Before Dr. Danvers leaves, she tells the girls their father died in service for the DEO. He made a deal with Hank to work for the DEO in exchange for leaving Kara alone.

Hank congratulates Kara for capturing Livewire. When he walks away, the girls tell each other they need to find out what happened to their father.