Epilogue:

Supergirl, Arrow, Mia and J'onn were victorious at DEO. The White Martian had returned to his cell in the agency. Mia had been examined by Alex for her injuries.

Oliver went to see his daughter at the DEO's medbay.

"So how is she?"

Mia rolled her eyes, annoyed.

"Dad, I'm fine."

Alex hastened to answer:

"Fine which results in two broken ribs and a pulmonary contusion. I recommend a lot of rest. And that's not a request."

"I'm telling you I'm fine," retorted the archer.

"Mia, please, Alex told you to rest, so you rest," replied Oliver. "I know you are a fighter, I have no doubts about you, but you are not indestructible. So you rest. There is nothing to discuss."

"Are you talking as Green Arrow or my dad right now?"

"Both."

"Don't worry, Kara will keep you company," added Alex wanting to lighten the mood. "And more, she would like to do an interview to justify your rescue and that she did not have to answer Diaz's blackmail."

William joined them and looked nervous.

"Speaking Diaz, where is he?"

"Ricardo Diaz is currently detained in our cells at DEO with two Black Mercies embedded in the body," announced Alex proudly. "And for now… nobody here wants to release him. I shouldn't say that but... I prefer to leave him that way."

"The feeling is shared," replied Oliver with a smile.

The archer was resentful to the criminal for trapping him with the alien plant. He had planned to kill him, but this punishment relieved him. At least he didn't have to commit murder. And he was happy. Before the Leviathan crisis, Oliver had prevented Mia from killing Grant Wilson. What image of a father would that give him if he had killed Diaz? He had managed to curb his murderous impulses.

"The longer he stays in his dreamworld, the better that will be," replied Mia. "But do I really have to stay in bed?"

"Yes," replied Oliver and Alex in chorus.

"Don't worry, Sis, I'm going to keep you company during your recovery," added William, settling down next to his sister. "Did I tell you how happy I am to see you again and that you're not dead?"

"I think you told me a good ten times," sighed Mia, tired.

"Seriously, did you really count?" wondered her brother.

Oliver and Alex shared a mischievous smile while leaving the children of the future to the medbay.

Supergirl flew over the city of National City, patrolling each building in search of Leviathan. She was assisted by Green Arrow, Spartan, J'onn and Dreamer. But since they arrested Diaz, it was as if the sect had disappeared. Two days patrolling the city, they all returned to DEO empty-handed.

"Do you think it's worrying not to hear from Leviathan?" asked Dreamer.

"William hasn't had any contact with them recently," said Oliver.

"We were wrecked them havoc," said Diggle. "In my opinion, they will be discreet."

"And with Diaz out of harm's way, they're not going to risk attacking the DEO again," J'onn added.

"I'm sure William and Mia won't be risking anything anymore," Kara replied. "You can leave on Earth – 1 in peace."

"That's what I thought," said Oliver.

"The day they come back, we'll be ready to receive them," added the Kryptonian.

The archer was convinced of his friend's reasoning. Leviathan had just competed against Supergirl and Green Arrow. Their enemies had surrendered from the power of the two superheroes. And that William and Mia were out of reach with their overprotective father. They were not going to risk attacking them again. And knowing that Diaz was defeated reassured Oliver. His children had nothing more to fear, just like Supergirl. He was relieved that his friend had not had to reveal her secret identity.

In more, Mia knew that Diaz had transmitted his blackmail to Supergirl to the whole city. She had asked Kara if there would be a way to tell the people of National City that she was saved and that Supergirl had not had to reveal her secret identity. Kara then offered to make an announcement via CatCo, the newspaper she worked for. She even offered to interview her. Mia had accepted while keeping her anonymity. In Kara's interview, she told how Supergirl had managed to find her and rescued her before Diaz had finished her. Green Arrow, being a vigilante from another Earth, Mia and Kara had agreed not to mention him. In the end, both were satisfied.

The next day, the front page of CatCo magazine unveiled the interview with the girl rescued by Supergirl, written by Kara Danvers.

"Was that enough for a first page?" asked Mia.

"You're kidding, my boss was delighted when I showed her the interview," Kara replied laughing. "Besides, Diaz was a madman. People will quickly forget him in no time."

Even Oliver was satisfied with the article and congratulated Kara for the interview.

Finally, Mia could leave the DEO's medbay. Before leaving on Earth – 1, Kara had proposed to Team Arrow, a karaoke evening at the Bar of Aliens to celebrate their departure. To everyone's surprise, Mia agreed and even wanted to sing on stage with Kara.

In the evening, Alex, J'onn, Oliver, Brainy, Nia, William, Diggle and Connor were gathered around a table, while Kara and Mia were on stage in front of the microphones. The two started singing "We Are Powerful" and dancing at the same time.

"We are invincible, we are unique
We Are incredible, we are free
We Are beautiful, we are a dream
We Are wonderful, you and me

We Are Powerful

We Are Powerful"

Their friends laughed and cheered them on. Oliver was stunned and laughing with happiness at the sight of his daughter singing. Even William and Connor were amazed to see Mia dancing and singing along with Kara.

"Did you know she was singing?" Oliver exclaimed to his son.

"Nope, I didn't even know it until tonight," replied William, ecstatic at the sight of his sister singing.

Kara and Mia continued their song while dancing:

"We Are Powerful

We Are Powerful"

When they were finished, everyone cheered them on. Then they joined their loved ones at the big table. Kara congratulated Mia.

"That's really good!"

"Thank you, you're an excellent singer, Kara," replied the girl of the future.

"Oh thank you, Alex says I put the "Kara" in "karaoke"," clarified the Kryptonian. "And more, I always had a liked the Wizard of Oz."

"Really?" exclaimed Mia joyfully. "My mom made me discover this film very often when I was a kid. That makes us one thing in common."

When the two women settled in, Oliver hastened to congratulate his daughter:

"You were amazing! I don't think that it was Nyssa who taught you to sing like that!"

Then he laughed, imagining Nyssa Al Ghûl teaching her daughter to sing.

"Sorry Dad, but it's a secret from the future," replied his playful daughter.

"Oliver, I like your daughter," replied Kara, amused.

"Well come on, it's my turn to sing," replied Alex, going on stage.

And the elder Danvers began to sing "Breathe":

"2 AM and she calls me 'cause I'm still awake
" Can you help me unravel my latest mistake?
I don't love him, winter just wasn't my season "

Yeah we walk through the doors, so accusing their eyes
Like they have any right at all to criticize
Hypocrites, you're all here for the very same reason

And 'cause you can't jump the track, we're like cars on a cable
And life's like an hourglass, glued to the table
No one can find the rewind button, girl
So cradle your head in your hands

And breathe, just breathe

Oh breathe, just breathe "

The moment had arrived. Oliver, his children and his team were going back to Earth – 1. Before leaving, Supergirl had asked to see Mia. She had taken her to a DEO equipment room, and brought her to a large case.

"Before you leave, Mia, I want to give you something," said the Kryptonian with a smile on her lips.

She opened the clasps of the case and invited the young archer of the future to open it. Without questioning Kara's secret about the contents of the box, Mia approached the table and opened the case. Her jaw dropped when she saw a brand new bow almost identical to the one that was broken. With a puzzled smile, Mia took the bow in her hand and felt it.

"I felt guilty that Diaz destroyed your bow, so I asked Brainy to do that," said Supergirl, beaming. "Technology of 31th century. The arc is made from a Nth metal. A metal that comes from a planet called Thanagar. It is a hundred times more resistant than steel. The strongest in the whole galaxy. Even I couldn't destroy it."

"No way?"exclaimed Mia stunned.

"Yes," assured the Kryptonian. "I thought it would be unfair for you to go back to your Earth without a bow. I saw you did and… I told myself that it was necessary to remedy your broken bow."

Mia inspected her bow, amazed by her new weapon. She raised the bow, lightly testing the cord before turning to Kara, her smile as big as hers.

"That's… That's perfect… Wow! I can't wait to use it. Thank you, thank you very much…"

"You're welcome", replied Supergirl blushing.

Towards the entrance to the room, Oliver stood nearby. He watched his daughter from a distance with Supergirl. He was grateful to his friend for making her a new weapon. Mia put the bow down and turned to her friend.

"Supergirl Kara … … Thank you for helping us save… William… save me too… and I was really happy to have met you. Meeting you was the best thing that could have happened to me. Before you, there was my father… Team Arrow… for a time, I thought the vigilantes were rotten. I know today that I was wrong. In 2040, for some Green Arrow is considered a hero, others see him as an outcast. And when I see you… I understand what people see in you. What you represent for them. You are a real hero. A symbol of hope. That was what I needed. The people of this Earth are very likely to have a Supergirl. I really wish I had someone like you in 2040. If my future had had a Supergirl, I'm sure things would be very different. There wouldn't be all this corruption and chaos in Star City. It may be selfish to say that…"

"No Mia, it's not selfish," replied Supergirl. "It's human. And I'm very flattered that it looked that way on the outside. Today is in 2019. It's not too late to fix your future. Make it better. One thing I learned by saving the world with your dad and the Flash is that you can control your destiny. And that there is no fatality. There was a time when there was only me and my cousin. And it was when I met Barry Allen and your dad that I realized that heroes existed even though they weren't Kryptonians."

"I'm glad you didn't reveal your secret to the whole city," said Mia. "My dad's reputation was never the same after he denounced himself as the Green Arrow, and I feared you would suffer the same fate. You really didn't deserve this, and I would have wanted to."

"Your dad is to be congratulated on this," replied Kara. "Because I was on the verge of doing it. But he assured me that you were strong and that you would send us a signal. And he was right."

"I think I owe you an apology," added Mia.

The Kryptonian raised her eyebrows, while the young archer continued:

"When we met, I was not very nice to you, and I'm sorry."

"No, you don't… I understand you… When I met your dad for the first time, at first, it was hard to get along both. We didn't like each other at all. Then we had to save the world together. We worked together, that's what made us friends. And honestly, even if you weren't able to grow up with him, I think you look like him… more than you think."

In his corner, Oliver, who was listening, could not help smiling wistfully as he remembered his meeting with Kara during the invasion of the Dominators on Earth – 1. Mia was touched by Supergirl's words and hastened to continue.

"By the way… don't blame my father for his pact. Before we went to rescue William, I heard you on the balcony. I'm not a Kryptonian, and I don't have super-hearing, but I can listen. I know what my dad sacrificed to save you and the Flash. And I think he was right to do so. It was the right decision. I don't want you blaming him for doing this."

"I don't blame him, Mia," Kara assured him. "What bothers me is that it forced him to abandon you and that you had to live without him."

"If my dad had never left, I don't know what would have happened to me, and anyway, we'll never know," replied Mia, shrugging her shoulders. "Today, I finally have the opportunity to be with my dad… and I met you. Thanks, Kara. Thanks to you, I know what the word hope means. Now I have hope for a better future. And it was you who inspired me."

And to Supergirl's surprise, Mia came to hug her. Kara returned the hug, moved.

"Your dad wouldn't do that to me!"replied the Kryptonian.

"Really, Kara?"

The two turned to see Oliver coming towards them, a smile on their lips. And he also came to hug Kara against him.

"I thought you didn't like hugs, Oliver!" exclaimed Supergirl.

"People are changing, Kara," replied the archer. "I'm not a Kryptonian, and I don't have super-hearing, but I, too, can listen."

There was an awkward silence, then Mia closed the box and took it with her.

"I'm going to go see William and Connor. I can't wait to go back to Earth – 1."

As soon as the young archer walked away, Supergirl looked at Oliver.

"I was delighted to have seen you again."

"Me too. And thank you for what you did for Mia and for William. What I told you how you and Barry inspired me, I was serious."

Supergirl smiled, then looked nervous.

"Your children don't know about your fate in the Crisis?"

Oliver shook his head in response.

"You will have to tell them soon…" Kara continued.

"I know that."

"Whatever Mar Novu may say, I hope we can prevent that! I can accept that you sacrificed everything you had for Barry and me, but I cannot accept that you die for us. Oliver, there must be a way."

"Kara, I hear you," Oliver assured her with a smile. "But I have a feeling that everything will be fine. And whatever the outcome of this Crisis, always continue to do Good around you. You are Supergirl and you symbolize hope. I hope everything will be fine for me, and for Mia and William."

Supergirl nodded, then added with a smile on his lips:

"Honestly, I think fatherhood is doing pretty well for you, Oliver. You and your daughter have a lot of similarities. Like father like daughter."

"It's weird, isn't it?" replied Oliver still smiling.

"No, I like it, and it makes you smile", added Supergirl, laughing.

"Kara…" said the archer, groaning a little.

Later, all were gathered in the center of DEO. The heroes said goodbye. Dreamer saluted Team Arrow.

"That was a pleasure to meet you," said the young hero in blue.

Then Oliver came to shake J'onn's hand gratefully.

"Thank you again for your help, Mr. J'onzz," said the archer to the Martian.

"It's J'onn. And you don't have to thank me. I was a father a long time ago. Today, I consider Kara and Alex to be my daughters. I know exactly how you feel."

Oliver nodded, then hugged Alex.

"Thanks for everything, Alex."

"You're welcome. Thank you for what you did for my sister."

Connor and William came to hug Supergirl against them.

"It was great to have you meet Supergirl," said the young black man.

"And thank you for freeing me from Leviathan," added William. "I finally hope that we will return to Earth – 1 without incident."

"If it doesn't work, I have my extrapolator for Earth – 1," assured him Supergirl.

Then it was John Diggle who greeted everyone and hugged Kara. Finally, all were ready for departure. Mia clutched the box in her hand, impatient to use her new bow, while Oliver pulled the extrapolator out of his outfit and activated it, creating an interdimensional breach.

Dig, William and Connor were the first to cross it.

"See you soon," greeted Diggle as he walked through the portal.

William and Connor greeted everyone and joined them in the vortex.

Mia took one last look at the Kryptonian.

"Supergirl, if you ever find these Leviathan bastards, say goodbye from me."

"I will," Kara replied, nodding.

"Goodbye, Kara," said Oliver.

"Goodbye Oliver, goodbye Mia," Supergirl said to them. "Take care of yourself."

"You too," replied the young archer.

And finally, the father and daughter made their way to the portal which closed in on them. They finally returned to Earth – 1.

Supergirl, Alex, J'onn, Dreamer and Brainy looked at the location of Team Arrow.

"You have great friends, Kara," said Dreamer.

"I know," said Supergirl.

"Green Arrow is an amazing friend. Do you think we will see him again soon?" asked Alex.

"I think we will soon see it again, with what will happen soon," replied Kara, thinking back to the future Crisis.

Earth – 1; Star city

In the dark alleys of the city, two thieves tried to escape from the police force by sneaking behind containers. Once the police sirens were silent, the two criminals sighed in relief.

But they ignored that they were being watched by two archers, above them. Green Arrow stood on a roof, with his daughter Mia, near him, brandishing her new solid bow.

Mia shot several arrows which neutralized the two thugs. She smiles as she looks at her new weapon.

"Thanks for the bow, Supergirl."

Green Arrow approved his daughter, satisfied.

Not only did Mia hold the bow in her hands, but also kept the Supergirl signal watch on her handle. Because she still had hope. She had learned to hope. See a better future than the one she knew. And she would fight for it. She would fight to the end.

"Dad, you really have an amazing super friend!"

"The best,"replied Green Arrow, delighted.

END

And so ends this story. I hope you enjoyed reading it that I had to write it! I have another Supergirl / Arrow crossover story in mind. In fact, I already had it in mind for several months already. But it was very important to me to do "Lost Children" first, you will understand why later. I didn't think I would go this far with this story and I'm proud of the result. I will now devote myself to this story.

And I still want to thank Amelia-Queen-Black, for inspiring me. It is thanks to her that this story was made possible. THANK YOU VERY MUCH!

For the karaoke scene, I had the idea of making Kara sing with Mia. Because Mia's actress, Katherine McNamara is also a singer. And we've already seen actors from the Arrowverse sing.

And Alex's song Breathe is a reference to the Grey's Anatomy series, where actress Chyler Leigh sang this same song in an episode of this series.

While waiting for a new story, take care of yourself and see you soon for a new story. But if you have story ideas related to "Lost Children" I am interested.