Note: This is my first Transformers (Bayverse) and Supergirl (2015) crossover. Please, don't judge. Thank You and Enjoy!

Chapter: One

A hand was placed on the Prime's shoulder, "Don't worry Optimus, we'll find her." Hound said to his boss as Optimus Prime was standing on a cliff in Nevada, looking out in the distance. He was worried about his sparkmate. Was she okay? What if she was in danger of being hunted because of him? He can feel in their bond that she's alright. For now. But what happens in the next hour? Or the next day? He didn't know and that scared him. It was only a matter of time.

It was only a week ago when he met the most incredible woman in the universe.

One Week Ago

Kara let out a grunt as she was slammed into a car, denting it with her indestructible body as she fell on the road. She looked up to see the Decepticon walking towards her, she stands up and flies towards the robot as he fires his guns, Supergirl dodges them as she flies straight for his chest as she broke through and came out on the other side as she turned around, hovering in the air and watched as the robot fell to the ground. Dead.

This isn't how she had planned her day; she was in Chicago on business for CatCo when the fighting started, it wasn't hard for Kara to tell who the good guys were and who were the bad guys. She had known about the Autobots and The Decepticons from J'onn who agreed to partner up with NEST.

She heard blasters firing as she looked to see Optimus Prime fighting a flew towards that direction, decepticon was just about to fire again when, "HEY UGLY." She yelled, gaining the attention of the two bots as she flew by and punched the Decepticon in the face, sending it crashing down.

She flew over to the downed Autobot and held out her hand, "Come one. We got a city to save." she said as he grabbed her hand and she grunted as she pulled him up.

"Thank You." he said as Kara nodded. Just then they looked to see the robot getting up and he didn't look happy. "I'll distract him while you kill him." she said as he nodded.

"Kryptonian! Ah!" The decepticon roared as he got up and started firing his weapons. She flew towards the robot, dodging his bullets with precision, it was just enough of a distraction as Prime unsheathed his sword and stabbed the robot from behind, blade sticking out from the chest. He pulled it out as the robot fell to the ground.

The Autobot turned towards the blonde hero, "Thank You Supergirl. We couldn't have defeated the Decepticons without your help." he said as Kara smiled and nodded, "No Problem and please, call me Kara." she introduced herself as the Prime hummed, "I am Optimus Prime. It's a pleasure to meet you Kara." he replied as Kara smiled. "It's a pleasure to meet you too." she said as she flew away.

Present Time

"Optimus." He was brought out of his thoughts by hearing his name calling and turned to see Drift approaching him. "I think you should see this." he said as a holo-screen popped up for everyone to see, "It's a program that humans watch to let them know what's going on this planet. But that's not the reason why I called." he said, "This is why." he added as the screen switched to a news broadcast with the image of Supergirl and in bold letters on the bottom:

"Supergirl Identity Revealed."

"This just in, the Identity of Supergirl has been released by an anonymous source. Kara Danvers, an employee at CatCo Worldwide Media is without a doubt, The Girl of Steel." Said the newswoman, as a photo of Kara popped up beside the Supergirl image, just then they were replaced by a short video appeared beside her of people with angry faces burning Supergirl merchandise. As you can see, the citizens of National City are furious and feel betrayed by the hero, all asking one simple question: Why?" The video disappeared as it was just the news woman.

The President has also dispatched a strike team to hunt down Supergirl and reinstated CADMUS, a rogue government agency that's main goal is to eliminate all aliens including their #1 target of interest: Supergirl (aka) Kara Danvers. CADMUS, who had also paired up with Cemetery Wind and the KSI to help aid in the search for the Autobots as well as Supergirl. We'll get back to you as this story develops."

When it was over, it was silent for a few minutes before Optimus let out an angry yell as he punched a nearby rockface causing it to crumble. Face filled with fury, "AUTOBOTS ROLL OUT! WE MUST FIND KARA BEFORE THE HUMANS DO." He ordered as he transformed and sped away with his team following him.

Three Months Later

It has been three months since Prime and the Autobots have seen the news and ever since been looking and searching for Kara. They were on the outskirts of National City traveling down an isolated road, when suddenly Optimus let out a grunt as he transformed, on his knees with a hand on his chest. "Optimus? What's wrong?" Crosshairs asked as the others transformed.

"It is Kara. She is in trouble." he said as he looked up, "This way." he added as he transformed and drove off the road to a trail leading into a forest at high speeds, following their bond with his team following behind.

XxXx–

Kara winced as she ran for her life, panting as her heart beating against her chest while holding her side where the kryptonite shard resides where she was shot. It wasn't supposed to be like this. It started three months ago, after her identity was released, the government and the KSI were hunting down the Autobots, and KSI had paired up with CADMUS to go after Supergirl, so not only CADMUS is after her, so are Cemetery Wind and the KSI. She just hoped that Optimus was okay and safe.

She stopped next to a tree to rest and take a deep breath before letting out a groan, she was still in her Supergirl suit that was dirty, along with her face that was also dirty and had some rips in the cape and skirt as she looked up to see nothing but more forests, "THERE SHE IS!" Someone yelled as Kara gasped and looked back to see CADMUS agents with their guns as she ran but not before she almost fell down, causing her to stagger but regained her balance. She would use her speed, but the kryptonite embedded in her side made it impossible.

She continued to run as she looked back to see if they were still behind her, just then she felt something piercing her other side as she screamed in pain and was sent to the ground. She groaned as she looked to see it was Lillian Luthor holding a kryptonite taser, "We meet again Supergirl. This time, you're mine." she said as soldiers surrounded her, aiming their weapons that she knew had kryptonite in them.

Oh Rao, please help me. Prime where are you? She thought as she closed her eyes tightly, getting ready for the worst. "GET AWAY FROM HER!" said a loud voice as she opened up her eyes to see it was Prime and his team of Autobots, his face filled with rage as he and his team took care of the soldiers and shot at them with their cannons as a few managed to escape. Lillian Luthor didn't look happy, "I'll get you Supergirl. You're mine!" she exclaimed as she ran away.

Kara whimpered as she tried to move but let out a yell, "Don't move Kara." Prime said as she stopped moving. She watched as he crouched down, "Y….You came back for me." she whispered as Prime laid his big hand gently on her face, "I would never leave my Mate." he said as Kara smiled but winced as he carefully removed the tasers and he examined her wound as he used his scanner from his eyes. "You'll be okay. Nobody will ever hurt you again. I am so sorry for leaving you." he said looking into her beautiful blue eyes, his face filled with regret.

"It's….It's okay Optimus. They….they were gonna come after me if you…would've stayed." she said as he shook his head. "Look, what has happened. My mate is hurt. Hurt by humans." he said with hatred as he gently slid both servos underneath her and picked her up as she let out a groan. "Shhh! I got you, my dear, you're safe.'' he said in a gentle tone as he walked away.

While walking deeper into the forest, Optimus looked down in his servo to see his mate was unconscious. He knew she was in pain, he could feel it in his spark. He didn't like seeing her in pain and it angered him that she was hurt. How dare they hurt what was his? Soon, he's gonna get the humans who did this. Despite their #1 rule about harming humans, he will not hesitate to hurt any human who tries to hurt Kara. He would protect her until his spark went out. To the end of time. Because that was how much he loved her.

XxXx–

When Kara woke up, she slowly opened her eyes, at first she didn't know where she was. Just then everything came back to her as her eyes widened in fear, she tried to move but let out a groan as her face scrunched up in pain. "Easy Kara! Don't move too much." said a voice.

It was familiar, but comforting, she opened her eyes to see it was just Optimus. She looked around with her eyes before landing on the mech, "C…CADMUS?" She whispered in fear feeling her heart drop. Optimus lifted a digit and gently caressed her face in a loving manner. "It's alright Kara. They're gone. You are safe." he said as Kara nodded and felt tears in her eyes, the last three months finally taking its toll on her.

"Thank Rao, I was….I was worried about you. I…I didn't know if you were captured….or…." she stopped as she let out a gasp at the pain in her side as tears made its way down her face at the thought of him being captured and closed her eyes.

She felt a metal digit, gently rubbing her face as she opened her eyes to see Optimus, his face filled with love, "Easy my dear, I'm alright. I am right here." he said, comforting her as Kara nodded and smiled. "Rest now. I will be here when you wake up." he said as Kara sniffed. "Promise?" she asked, filled with hope.

The mech nodded, "I promise." he said as his digit played with her hair in a loving manner.

XxXx–

When he made sure she was asleep, he stood up and quietly walked out of the abandoned barn out in the middle of nowhere. It didn't look like anyone has been there for a very, very long time as it was starting to rot. It was a perfect hiding place for the Autobots at the moment, plus it was tall enough for them to walk out while in their cybertronian form.

He stepped outside to see his team standing there waiting to hear the news about Kara, he nodded. "She is gonna be okay. She woke up a few minutes ago but is now resting." he said as the others were relieved.

"Thank Primus." Hound said as the others nodded.

"She's one strong kryptonian." Drift said. They were all glad that Kara was going to be okay. "We will take turns keeping watch tonight Prime, Kara is one of us. We'll make sure no humans come anywhere near her." Crosshairs said as he activated his cannon as proof. Primes spark filled with warmth at his team's deviation and loyalty to him and to protect Kara.

"I thank you. All of you." he said as he turned around and walked back inside the barn, he carefully picked up Kara, who was still sleeping and gently transformed around Kara to where she was laying in the bed in the cab of his truck as he shut down and went into recharge.

They have a big day tomorrow and they're gonna need as much recharge as they can for what's to come. Because, if there's one thing that they all knew: CADMUS will not stop till they have Kara in their grasps. Tomorrow, they will roll out, heading towards the border into New Mexico.

What did you guys think? Leave reviews at the bottom. I wrote this as an experiment to see what it will get, and to see how people feel about this pairing. But I will write another Chapter if this get's anything. Be honest! Thank You.