A week after revealing herself to National City, Supergirl's abilities were put to the test by Hank Henshaw and the D.E.O.. While flying, Kara complained to Henshaw over a head set whether or not the tests were mandatory for everyone, or just because she was an alien. Thinking she was going to say because she was a woman, Hank explained to her that the tests were mandatory for all prospective field agents. Continuing on, Hank told her that a new superhero could in fact be a liability and as such he needed to know if she was in full control of her powers. After breaking the sound barrier, simultaneously a glass board when flying past the DEO camp, Henshaw ordered for two more missiles to be fired at Supergirl. Kara successfully evaded the missiles, making the two bump into each other and explode. Landing at the DEO camp, Kara asked Henshaw whether she passed, though he noted that she shared Superman's appetite for wanton destruction. After talking to Henshaw, Kara asked her sister, Alex Danvers, whether all of the tests were necessary as she felt that she was ready for all of it. Alex told Kara that whether she believed it or not, Henshaw was simply looking out for her, and that she had gone through a full year of training before being let out into the field. Sighing, Alex expressed to Kara that she was really glad she was there, and that she hated keeping the DEO aspect of her life from Kara. Soon after, Kara was contacted by Winn Schott over her earpiece, being alerted to a huge fire occurring at the National City Port. Telling Winn that she was on her way, Kara was warned by Alex that she had been pushing her endurance for the past two hours, and that even she had her limits. However, Kara told Alex that for the past twelve years she had hid who she was, and seeing as she didn't have to anymore, she didn't want to waste a minute of it.
At the National City Port, Kara asked the fire chief what could she do to help. He explained to her that the ship near the Port was holding a million barrels of of crude oil, and if the fire reached it, it'd explode. Attempting to cease the fire by using her super breath, a firefighter complained that Supergirl was making the fire worst. Choosing to try another method, Kara unattached the ship from the Port using her heat vision, and pulled the ship away from the Port by it's hull. However, while doing so, Kara ripped open the the Hull releasing oil into the bay. The next day at CatCo Worldwide Media, Kara walked out of the elevator being met by Winn, who asked whether the smell was coming from her. Kara explained to Winn that even after three showers she still smelled of burning oil, expressing that she went from superhero to an eco-terrorist after the previous day's failed heroics. Attempting to comfort her, Winn pointed out that she was only a week into being a superhero, and that she was going to make mistakes. Turning their heads to the news, the two watched Maxwell Lord on television explaining that Supergirl would bring trouble to National City that it didn't need, and using Metropolis as an example, brought up that since Superman's arrival Metropolis' maintenance budget had double, as a super bad guy war had been waged on the city. Though Winn told Kara who cared what Maxwell Lord thought, Kara pointed that Winn did, asking wasn't Lord was his personal hero, which in turn forced Winn to admit to owning several of Lord's watches, and both his biography and auto-biography. Using her super hearing, Kara alerted Winn that Cat Grant had arrived, with Winn commenting on how he finally knew how she able to know that. Heating up Cat's latte with her heat vision, Kara met Grant outside her private elevator, giving her the latte, and being informed that content meeting was taking place in her office in two minutes.
In her office, Cat told everyone that she assumed they were all aware of Supergirl's latest heroic failure. Cat informed everyone that it was the lead story on the Daily Planet homepage, their fifth in as many days, and it annoyed her, because they already had a go to superhero and they were trying to steal hers. Continuing on, Grant made it known that when she branded Supergirl, their was an implicit promise that she'd at least be above average, and that in the past week she had proved herself to be the very opposite of super. This however, caused James Olsen to comment that Superman had made many mistakes when he himself had first started out, and that at least Supergirl was saving lives. Cat pointed out that she was doing so in the sloppiest way possible, and that it was up to them to save Supergirl from ruining her image, to take control of the heroine's narrative, and scoop the Daily Planet. Cat then announced that she wanted an interview with Supergirl. Snickering because of this, Kara told Cat it was because of a kitten video that she had seen earlier. Cat then asked James whether or not he could asked Superman to arrange an interview with Supergirl the next time they hanged out, though James told her that wasn't the way things worked. Finishing, Cat told the attendees of the meeting that Clark Kent, Lois Lane, and the rest of the Daily Planet employees were working day and night to get an exclusive with Supergirl, though they needed to get it first, with Cat wanting an interview with Supergirl by the end of the week. After telling everyone they could leave, Cat stopped Kara before she could do so as well, telling her assistant that she knew what was going on with her, and that she needed to get her head out of the clouds, whether that meant joining a gym or seeing a shrink, she needed to get her head back behind the desk where it belonged. Leaving Cat's office, Kara refused to do the interview with Grant, as she thought that Cat would recognize her within seconds. James however shot back that Cat wouldn't recognize her as Supergirl, because she didn't even see her now. Recalling that he watched it happen for years with her cousin, James reassured Kara, giving her a pep-talk after she doubted herself, telling him that she might have become a superhero too soon.
At Plastino Chemicals, two guards talked about the arrival of Supergirl to National City, with one commenting on how it was nice that National City now had it's own hero, and with the other retorting that the other guard had said the same exact thing when they had gotten their own professional basketball team. Walking into the building and going their separate ways, the guard caught a man filling a tank with chemicals. Asking the man whether or not everything was okay there, he was told that everything was fine, and that the man was just finishing up. Right after, the guard asked to see his ID, taking out his gun and asking the man to stand back from the tank, reporting on his radio that there was a sector breach in Sector 52. The man soon revealed his true form, causing the guard to run in fear. However, the guard was caught by the man who scaled the walls chasing after him, eventually landing on him and catching him. The next day, the DEO investigated the theft and murder of the guard, with Alex Danvers calling Supergirl to assist. When asked by Henshaw as to why she did so, Alex explained to him that as they hunted aliens, and Kara was one, she was a resource that they hadn't had before hand. Asking what she could do to help, Kara was told by Henshaw to look around, though to not touch anything. He then went on to tell Alex that Plastino Chemicals specialized in chemical manufacturing, including ingredients for a chemical bomb, and as such they needed to find the alien fast.
Years ago on Krypton, Alura Zor-El walked into Kara's room, questioning as to why she was still up. After telling her mother that she simply wanted to see her, Kara asked Alura why she had been working so late, and was told by the latter that a Hellgrammite criminal had been brought to the citadel. Kara told Alura that one day she wanted to help people just like she did, and Alura told her that she would as she had the heart of a hero. While at the DEO base, Kara remembered this, also remembering that her mother had sent one to Fort Rozz, with Alex noting that from the wreckage they salvaged from the Fort Rozz crash, there had in fact been a Hellgrammite prisoner. Kara attempted to offer to Henshaw that the DEO could track the Hellgrammite down, and she'd defeat him as they did with Vartox, though Henshaw came to the conclusion that they would only do so if she could prove to them that she could handle herself without being killed. Going into the DEO training room, Kara was defeated by Alex after Kryptonite emitters were turned on in the room, weakening Kara, though making it a fair fight. After Kara left with the sentiment that she know knew why Superman preferred to work alone, Alex told Henshaw that she hated that he had made her do that.
At CatCo the next day, Cat asked Kara why she was walking strange, with Kara excusing it as having had took a kickboxing class, and as such was sore. Kara soon read the latest headline written by Cat, and asked her boss why she was intent on criticizing Supergirl when she was trying to save the city. Cat explained to Kara that Supergirl had been taking on too much too early, that there was a learning curve, and that Supergirl needed to start small and work her way up. Leaving Cat's office, Kara told Winn to meet her in the alley in five minutes. Walking out into the alley, Winn encountered James, and after the two attempted to get each other to leave as they were both meeting someone there, they were surprised to find out that both of them were confidants of Kara, and each knew her identity as Supergirl when she landed in front of them. After their initial surprise, Kara old the two that if she was going to be a hero, she'd need to practice and needed their help, with the both of them telling her that they were in.
At a warehouse, the Hellgrammite was confronted by two Kryptonian underlings of General Astra. The Hellgrammiate attempted to explain to the two that he didn't want any trouble and he had to eat. Commander Gor however told him that if he didn't want any trouble he would have stayed hidden, and reminded the Hellgrammite that Astra had promised to take care of all of their needs on Earth in exchange for his loyalty. He was soon confronted by Astra herself, who told him that they were stronger together and he'd help her capture her niece, Supergirl, acting as a bait. When the Hellgrammite attempted to decline, Astra made it clear that it was a command and not an invitation.
Meanwhile, Kara asked what jobs James and Winn had for her. The two alerted her of several of emergencies, with Kara preventing a pizza place from being robbed, rescuing an ambulance stuck in traffic, and saving a young girl's snake from a tree. Later at her apartment, Kara watched the news with Winn and James, excitedly telling the two that people were starting to believe in Supergirl. James corrected her, by telling Kara that they were starting to believe in her, and Kara thanked James for his help, expressing that she couldn't have done it without him. Kara soon answered her apartment door for Alex, and was later questioned by her sister as to whether telling James and Winn her secret identity was a good idea. Kara expressed that it was a good idea as they were her friends, and soon after received an apology from Alex, who regretted how she handled things at the DEO. However, Alex was soon called by the DEO who needed her back at the base, telling Kara that she'd call her.
At the DEO, Alex asked what the news on the Hellgrammite prisoner was, and was told by Henshaw that they had confirmed six similar attacks on chemical plants across the country within the past year. The two were soon alerted by Agent Hartmann that the Hellgrammite's blood wasn't carbon based like human's, but instead had a chlorine foundation. Alex then brought up the fact that each of the facilities that had been hit stored confiscated DDT, and that the Hellgrammite was eating it, as the government had been destroying remaining stockpiles, and his food source was shrinking. At CatCo, James was summoned by Cat wanting to know if he had made any progress on getting any interview with Supergirl. James however told her that since Supergirl was in fact doing better, he wasn't sure if Cat was still interested in controlling her narrative. The two continued to discuss the situation, with James telling Cat that he had a policy of using his friends for business purposes. Cat however gave James the dilemma of getting her the interview within twenty four hours, or else he'd be fired.
Elsewhere in National City, the DEO set a trap for the Hellgrammite with a truck driving with tanks of DDT in it's back, and Alex and Henshaw along with several other DEO agents following behind it in another vehicle. The Hellgrammite soon arrived, jumping onto the vehicle with the DDT. After being shot at by Henshaw and Alex, the Hellgrammite jumped onto their vehicle, shooting stingers into several of the agents and abducting Alex, grabbing her and taking her back to General Astra. Outside of CatCo, Kara offered to do the interview with Cat Grant so James wouldn't be fired, he then revealed to her that things such as that had been happening for a while, and he thought coming to National City he could finally be his own man. Kara told him that on Krypton no one was their own man, and that it was an honor to accept help from others, and that apart of being his own man was knowing when to accept help from others. She then re-iterated that she was going to do the interview with Cat, though not for James solely, but for what they were accomplishing together. Kara then received a call from Henshaw who told her that Alex had been abducted.
At the DEO base, Kara berated Henshaw for putting her through tests instead of trusting her, as the situation could have been prevented if Kara had been there. Henshaw however reassured Kara that they had every satellite and a tactical drone searching for Alex, though Kara told him that they had her now as well. Flying through National City, Kara attempted to use her super hearing to track down Alex. At the warehouse, Astra commented on Alex's wounds, and how fragile human beings were. Mistaking Astra for Alura, Alex told the General that she had seen her in the message from the ship that had brought Kara to Earth. Astra revealed her true identity to Alex, and after being told by the latter that there wasn't a reason to kill her or anyone in National City, Astra told her that she was there to save them all.
Kara soon tracked Alex down with her super hearing, alerting Henshaw to Alex's location, which was at a warehouse on the corner of 78th and Washington. Henshaw alerted the other DEO agents to get together a strike team, as they were moving out. Arriving at the warehouse, Kara walked towards Alex, though was warned by the latter that it was a trap and to get out of there. Turning around, Kara was punched into the ground by Astra, who had remarked that it had been a long time since the two had seen each other. Getting up, Kara couldn't believe that her aunt was still alive, as she had thought Astra had died on Krypton. However, Astra revealed to Kara that she had been imprisoned by Alura in Fort Rozz, and wasn't on Krypton when it exploded. Astra warned Kara not to stand against her, and a fight between the two ensued. While attempting to contact the DEO through her radio, Alex was thrown into a chain-link fence by the Hellgrammite, though defeated him by forcing his own stinger into his heart. During her fight with Astra, Kara remembered what Alex had said about using an opponent's strength against them during a fight during their training session, and through Astra out the warehouse, through a window. Alex and Kara embraced afterwards, but were blown down by Astra's super breath. The two were then rescued by Henshaw who commanded Astra to halt. Though Astra grabbed Henshaw by the neck, taunting that he had no weapon that could hurt her, he plunged a Kryptonite knife into her arm, prompting her to fly off.
Later at the DEO base, Kara asked Alex to train her, with Alex promising to make Kara better then herself. Alex then took Kara to a room that had been set up for her, inside containing an artificial intelligence program that appeared in the form of Alura. Leaving Kara and the AI to talk, Kara asked for a hug. The AI however hadn't been programmed to do such a thing, so instead Kara asked for the AI to tell her about Astra. Outside of the room, Alex thanked Henshaw for helping her set up the room for Kara, with Henshaw telling her that it was the least he could do for Supergirl. At her base, Astra had the Kryptonite dagger pulled out of her arm. She then questioned her associate as to how the weapon could hurt her as Kryptonians were nearly indestructible on Earth. After telling him to get the blade away from her, Astra's associate told her that they'd have to re-think their timetable for taking National City as the humans were more resourceful then they'd originally thought.
Getting into her car, Cat Grant called James Olsen, telling him that even though she had given him twenty four hours, if he hadn't gotten her the interview with Supergirl already, she wanted to setup interviews with new art directors the next day. However, James informed her that her interview with Supergirl had already begun, telling her to look out her window. Doing so, Cat realized that her car was being carried by Supergirl. After the car was put down, Cat got out, and was told by Supergirl that James Olsen had told her that Cat wanted to talk to her.