In a very strong episode of Supergirl, punctuated by an unexpected team up, a declaration of love and two people butting heads on how to save a loved one.

And we begin with the two that are butting heads: Maggie and Kara/Supergirl. We open with Maggie in an intense hostage negotiation when Supergirl just punches her way in to diffuse the situation.

At a double date dinner at Alex’s, Kara and Maggie get into an argument on their different methods on the law. It ends with Kara storming off with Mon-el (and a couple of slices of pizza in tow). Alex asks Maggie to get along with Kara as it is important that the two get along. Maggie tells Alex she gets along with Kara fine, it is Supergirl that she has issues with. But Maggie agrees to make an effort. Alex then leaves to catch up with Kara to ask the same of her. As Alex enters her building’s elevator, we see a mysterious figure in elevator.

The next day, Maggie shows up at CatCo wondering if Kara has heard from Alex. Kara then gets a phone call that she thinks it is from Alex but it is from a man with a disguised voice asking Kara to break up Peter Thompson from prison in exchange for Alex. And the guy knows that Kara is Supergirl.

At the DEO, everyone is at a loss on how to find Alex since they can’t track her tracker. So J’onn as Hank, Maggie and Kara goes to visit Peter Thompson to find out why someone wants him out of jail. Thompson is not helpful at all and Kara loses her cool. But Kara losing her temper yielded nothing and J’onn knows Thompson is telling the truth about knowing nothing.

Meanwhile, Alex wakes up and finds she is in a glass cage and spies a video camera. Alex yells at her captor that she knows who he is and vows that he will pay once he gets out.

Luckily, the DEO has Winn and after going through Thompson’s visitor logs, we learn a frequent visitor was an unknown son. Winn IDs Thompson’s son as Ryan Malvern who is from Midvale, the same town as Alex and Kara.

Kara goes to Ryan’s address and finds a bank of security cameras and sees Alex on them. Ryan arrives and demands to speak to Alex. The two sisters have a brief moment and we learn how Ryan knows Kara is Supergirl. Ryan demands that Kara free his dad but she refuses.

Ryan is brought to the DEO and Kara asks how he knows that she is Supergirl. It goes back to the moment when Kara saved the woman and her baby from the burning car during their day at the beach with classmates. Ryan knew that Kara moved to National City and when Supergirl showed up, he out two and two together. The two then get into a bit of one upmanship about who had a harder life. Ryan tells Maggie and Kara that he was beaten by his mom but found freedom when he discovered a father he never knew who opened up a home to him. Ryan once again demands for his father’s release but Maggie refuses to free a man who plead guilty to killing two people.

Maggie then decides to use Ryan’s dad against him. We see Thompson visit Ryan at the DEO but he sees right through the ruse of J’onn posing as his father. Ryan does tell the group that he has been planning Alex’s kidnapping for a year after carefully observing everyone’s movement.

Back to Alex, removes the tracker in her shoulder and piggy backs it with her cell’s video camera to send out a distress call. Winn realizes it is Alex and tells Maggie and Kara. Kara ignores Maggie about taking things slow and think things through and goes to where she thinks Alex is. Unfortunately, it was another traop for Kara and instead of 36 hours to save Alex, she now has 4 with water rising in her glass cage.

Kara goes back to Ryan and shows the laptop video footage of Alex. The sisters talk again and Maggie arrives. Alex asks to speak to Maggie alone and Alex wants to tell Maggie something. Maggie refuses to listen as she wants Alex to tell her when she comes back. Maggie tearfully tells Alex that she wants to continue to have firsts with her like getting a dog. Ryan then gets into Maggie’s head that forces her to take Kara’s approach.

Maggie goes to break out Thompson but Kara arrives and takes Maggie’s approach and convinces Thompson to help them find Alex. The two ladies find Alex just in the nick of time before she can drown. It should be noted in a badass move, Alex fashioned her pants into a makeshift life preserver to give her more time before her rescue.

At the DEO, Alex is recovering and when she wakes up, she finally gets to tell Maggie what she wanted to tell them earlier that is that she loves her. Maggie reciprocates and the two share a kiss. To make things even better for Alex, her sister and girlfriend come to a better understanding of each other.

In our secondary storyline, Lena is entertaining a proposal from Rhea about using L Corp resources to make Rhea’s transmatter portal a reality. Rhea is passing herself as a MIT grad. Lena and Rhea bond over their family issues. Rhea mentions how her son broke ties from her because of his new girlfriend and shortly after her husband died. Rhea then offers up more information for their potential joint project but slips up by saying “thank the Gods”. When Rhea visits Lena in her office later, Lena confirms that her new found friend is an alien and tells Rhea she won’t help her. Rhea tries to get her to change her mind knowing that together they can make the transmatter portal a reality that can really help people. Lena still refuses to join forces and kicks her out of her office.

Rhea comes back to visit Lena in her Daxamite garb and once again tries to talk Lena into working together.

Lena tries to seek Kara advice but she is busy dealing with the Alex situation. However, later on we see that Lena had a change of heart and has decided to work on making Rhea’s transmatter portal a reality.

Next week, looks like we get a Rhea and Kara showdown.