This week on Supergirl, Kara finally learns the identity of Guardian and the gang teams up with an old enemy in order to defeat a new villain.
In “We Can Be Heroes,” Supergirl focuses once again on what makes someone a hero. Last episode, Mon-El said he wanted to become a superhero. This episode begins with Kara training him at the DEO. He does well, but still ends up with a causality, a cardboard cutout of a girl. Kara reminds him the most important part of being a superhero is protecting innocent civilians. Despite his error, she thinks he is ready.
Maggie arrives at a crime scene to find some men beaten up, while Guardian watches from a rooftop. James got shot during the encounter, and Winn is worried. He is also annoyed because now he has to fix James’s suit and make Mon-El one because Kara asked. Winn tells James he needs to tell Kara that he is Guardian and James reluctantly agrees.
M’gann is still in a cell at the DEO and starts hearing voices saying “Blood. Death. Beautiful War.” She shatters the glass with her voice and faints. Alex tells J’onn she can find nothing physically wrong.
Meanwhile, Livewire is having a therapy session in prison. She talks about how she wants to destroy Supergirl and says her power makes her a god. A thug disguised as a guard and another prisoner help free Livewire by shocking the therapist. Maggie and Alex look for clues in the prison cell. They hear Kara arguing with a cop and bet how long it will take her to get through. Alex wins the bet, so Maggie has to visit her place that night. Kara is flustered and worried about Livewire escaping, she thinks the villain will start killing civilians.
Back at the DEO, Winn and Mon-El are excited about facing Livewire, but Kara is agitated and ends up breaking something. In the infirmary, Alex tells J’onn know M’gann is dying. Alex asks if he will mindmeld with her to figure out what is wrong, but J’onn exclaims he will not share his memories with her and does not care if she dies.
In a different part of town, a group of cops are chatting when they are attacked. At CatCo, Kara arrives to talk to James, but ends up ranting about Livewire. James reminds her even though she is Supergirl, she is not alone. She thinks he means Mon-El, but he means Guardian. They talk about what makes a hero, but their conversation is interrupted by news of the attack on the police.
Mon-El and Supergirl arrive to help the police. They see a woman they think is Livewire, but the woman says she is not Leslie. The guard from earlier appears too, covered in electricity like the woman. Kara tells Mon-El to protect the cops while she fights both villains. He does, but then leaves the cops to try and help Kara. Guardian shows up and helps the cops, while the villains get away. Guardian is lying on the ground and Kara takes off his helmet, finally finding out that Guardian is her friend James.
At the DEO headquarters, Kara gets mad at her friends because she finds out Alex and Winn knew about James. She asks him why. He tells her he believes it is the best way for him to help people. Angry and hurt, Kara lectures him. James turns it around on her when she mentions Mon-El, since he left the cops to help Kara. Without James, more people would have been hurt. James tells her she does not get to make his choices, while she says she will stop him if he continues on this path.
M’gann’s condition is not getting better. Alex reminds J’onn that despite everything, M’gann saved his life. Kara catches up with Mon-El and demands to know why he failed to listen to her orders. She asks if he likes her and reminds him of the time he kissed her, but Mon-El does not really answer the questions and says he just wants to work with her. With Livewire and her gang still on the loose, Kara tells him she is going to find them alone. The irony is Livewire is not on the loose, she is being held captive and tortured.
Footage from the prison shows Livewire was kidnapped. Winn lies to the DEO, saying he cannot pinpoint her location yet. He calls James and tells him they can get Livewire to show Kara what they can do, but Mon-El overhears.
J’onn decides to help M’gann by mind melding with her and asks Alex and Kara to stay with him as he will see some terrible memories. He finds M'gann in her memories. She tells she set a fire and killed guards because they wanted her to kill a Green Martian boy. J’onn tells her she survives and meets him and saves his life as well. She tells him she cannot do anything about what happened to his people, but she wants to be friends. J’onn tells her he forgives her and they are friends, then they both wake up.
Meanwhile, the evil scientist who has Livewire is extracting her powers for his own super soldiers. She tries to barter with him, but is unsuccessful. Guardian arrives to rescue her, then Mon-El shows up and helps. However, the evil scientist catches them off guard and captures them both. Winn calls Kara and tells her what happened and their location.
The evil scientist starts to drain Livewire, but Supergirl arrives just in time. She frees Mon-El and James and then breaks Livewire free. They team up to take down the evil scientist and his associates. Livewire tries to kill the scientist, but Kara stops her and they make a deal. The scientist lives and gets locked up, and Supergirl gives Livewire time before she comes after her.
J’onn berates Winn for keeping valuable information to himself, but tells him he is impressed by what they have done. Kara tells Maggie and Alex she will take care of Livewire if she hurts anyone. While Maggie says since Kara let Livewire go, she won the bet and now Alex has to try vegan ice cream. James and Winn tell Kara they are going to continue and would like to work with her, but she firmly says she cannot support them because they will get hurt.
White Martians are coming, according to M’gann. She tells J’onn she tried to mentally block them, but failed so they know her location.
Mon-El is waiting for Kara at her home and finally admits he remembers kissing. He says he likes her and he knows she does not feel the same. Kara thanks him for being honest with her and they agree to continue working together.
This week was an interesting look at what makes a hero and who gets to decide if someone is a hero or not. James believes it is his choice and sees himself as a hero. Because of her abilities and experience as Supergirl, Kara believes she can tackle any task, but believes James cannot because he is human. She is worried for her friend and does not respect his choice. On the other hand, Mon-El wants to be a hero to spend time with Kara and to gain her respect and trust. Mon-El is not human, so Kara gives him the stamp of approval. Alex and Maggie are human, but they both face danger in their daily lives because of their jobs. It seems a bit out of character for Kara to be so angry with James for wanting to be a hero because he is human and breakable. Overall it was an interesting episode, but I hope Kara and James make up in the next few episodes.
Check out the preview for episode 11 of Supergirl “The Martian Chronicles,” airing Monday at 8 p.m. on The CW.