"Hello!" She greeted. The brothers blinked and Mikey grinned. Going up to greet her properly. Hand drawn out for a shake. One that was returned happily and then went down the line of the ninja quartet. "Nice to meet you guys, question. Do any of you know where to find a place of old artifacts? Preferably a book?"
The guys looked at each other. Than Donnie began typing something on his wrist tablet.
"Do you know what the name of it is? I need specifics to get close." Renet felt dumb, of course they need to know what it's called.
"Shit I don't know, my master just made me errand boy to go fetch something for a side project of his." Welp, she's fucked. It'll take a while before she gets that book, especially with only imagery to base her search off it. "Sorry to bother you guys. I'll leave you to whatever you were doing earlier." Beginning to walk away, she was pulled back by a large hand. One from the red masked turtle.
"Not so fast. You can't just portal here, introduce your mission and just dip." Oh yeah, things were different here.
"Sorry but I need to get that book. I'm not on time crunch, but it would still be nice to relax for a bit. Haven't really been able to recently."
"You're an open book aren't you?" Leo asked skeptical, a girl with a staff walks through a portal looking for an artifact that's old an it's going to help her master? Yeah no, sketchy. "I'm sorry but we're not helping you. I'm not putting my family in danger."
Renet seemed saddened but nodded her head. She understood. Of all people she was the one that most understood. She went to turn and leave but a voice made her freeze. 
"I'll go with her!" The brothers looked at Mikey like he was insane. "What? She needs help, plus who knows what kind of danger awaits with a magical being." Leo looked apprehensive but nodded his head reluctantly. 
"Come back safe and immediately after finding that book. Don't be stupid, and you," he looked at Renet who was smiling at Mikey. "Don't let him get hurt. Understand?"
It was kind of embarrassing for Mikey, he was 19 but still got treated like a baby. Regardless Renet nodded and made a salute gesture. Donnie huffed in amusement while Raph just stared. 
After heading off to the best place Mikey knew to have old things(library), Raph glanced at his older brother. 
"What?"
"Nothing, just, I don't know,... proud of you? Letting Mikey go on his own with a stranger." Donnie nodded his head in agreement. Sighing Leo gained an urge to go after the two but realized that would be stupid. Because in that case he should've just gone with in the first place. 
"Just hope he doesn't get hurt."
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He in fact, did get hurt. But, much less than Renet. After reaching the library they were able to gain a lead on where the book might be. An abandoned mine outside the city border. Teleporting there, they found Krang soldiers digging around the area. 
Renet had felt with them before. Specifically for them trying to conquer other worlds. Lord Simultaneous had fought their previous leader years prior, but a new one came to power right after. Taking in deep breathes she turned to Mikey. 
"You should go. They're small but they make up for it in numbers." Shaking his head rapidly, Mikey rebutted. 
"Nuh uh, I'm not leaving you here. Especially when we're so close to getting that book. You can count on me Ren." With a million thoughts racing, Renet was trying to think of a way to not get this giant goofball hurt. She promised his brother he would be home. Safe.
"Alright, here's what we're gonna do,.." It went smoothly. For the first part. Sneak around the Krang soldiers and make sure they're not seen. Easy. Get the spot where the book is? She could make a portal but that'll make a bright light giving away their hiding spot. Being discreet was better. Did that take Mikey bridal carrying Renet for a bit? Yeah, did they both enjoy that? Maybe too much. Then they found the pedestal with the book on it. Perfect. "Run Mikey!!"
Krang bots had gotten into the cave where mystical artifacts, including the book and the duo were hiding. Aiming lazer guns at them, Renet lifted the terrapin with her powers and launched him through a portal. One that shot him to edge of the forest a few miles away from the fight.
As he was flying through the air, a few stray shots scraped Mikey's arms and legs. When the portal was closing a shot hit Renet in the back and the portal closed. Frantically, fighting through the pain, he ran to where they first found the cave entrance. Hoping he could make it on time. 
Halfway there,(or wherever Mikey was going) a portal shot out from above in front and Renet blasted through unconscious. Jumping, he caught her and ran back home. Praying to whatever god was out there, and she believed in to give them mercy.
Trying his best to not be noticed by random civilians. Grabbing his phone and ringing up his brother who never sleeps.
"Donnie! Get the med bay ready, Renet's hurt, bad!" Quickly rushing over to his little brothers side, Donnie assessed the injuries on the blonde and took her into his lab. She had second degree burns on her arms, some forming to third and had open wounds that were glowing green.
"What attacked?" He asked trying to cool down the burns and figure out how to heal her without turning her into a mutant.
"Krang soldiers. They had these crazy guns, she threw me out of the battle before I got injured." Donnie glanced at his brother. Only minor burns and cuts that would heal later tomorrow. Finally noticing the other two terrapins were there they dragged Mikey away from the lab letting their mind gifted sibling space to focus.
Mikey was quiet, but wasn't staying still. Kept pacing back and forth. Rubbing his face in his hands, cracking his few knuckles from time to time and Leo felt guilty. A while ago he was talking shit about Renet, giving her a bad rep without even knowing her. It felt worse seeing his brother be anxious, especially when he's usually so optimistic.
Raphael, bless his soul, was trying to distract Mikey but all it did was make Mikey more anxious. More nervous. After what felt like days, Splinter was able to convince his youngest to sit down and rest after the excitement he went through. Getting him his favorite flavored tea(Hibiscus), the doors to the lab opened and Donnie came out with a limping Renet. She was using her staff as a walking stick and was going up to Mikey.
"Glad to see you alive," she said making Mikeys' eyes shoot up and regaining life in his pupils. Watching as third part felt like watching Mavis and Johnny from Hotel Transylvania zing. Maybe having her around wasn't as bad as he feared.
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"You got the book, then?" Renet nodded and pulled it out of her bag hanging on her belt which shouldn't have technically fit but seeing as she was a space wizard, Leo wasn't questioning much anymore. "Are you leaving?"
At this, the girl went silent. Smiling sadly, lifted her head up to look at Mikey and Raph playing a video game on the couch from the kitchen counter. Sighing softly she put her head back down.
"My master needs this. Besides, not like I can't visit." She said getting one last drink of the Crush soda Mikey had given her and walked away to say goodbye to Splinter. Whilst that was happening, Leo went to get his brothers ready to bid farewell the maiden who saved their sibling.
"She's leaving after saying bye to us. So if any of you want to ask anything about her dimension make it now. She's exhausted and apparently needs to train later." Pouting, Mikey and Raph paused the game and got ready for Renet to come back to the living room and say bye.
"Thank you again for letting me gain my strength back Master Splinter. I'll bring some tea leaves from my hometown as a thank you next time I visit. Promise it'll be sooner than you think too." Mikey got excited at that last bit, as well as Donnie. He couldn't wait know what kind of advantages magic with science could give. Also the dangers. Guess only time can tell and show now.