Disclaimer: Alec and Clary are best friends by the last book. I wish, so nope anddddd nope.

Summary: "Clary, the last time I offered myself as a test subject-" "See, you offered!" Alec continued as if he hadn't heard her. "I almost came out to my parents that I was gay and dating a Downworlder." Thanks to Ithuriel, Clary is able to create new runes to aid the Shadowhunters, and who better to test the power of the new runes than the eldest of the Lightwood siblings?

"No."

"Please?"

"No."

"Pretty please?"

"No."

"It's just this one rune!"

"NO!"

"Alec!"

"No matter what you say, the answer is still no! I want to read, so out!"

"It can't be anyone other than you!" Exasperation fast reaching full blown annoyance, Alec all but slammed the book shut and turned to look at Clary, arms folded over his chest. "And why does it have to be me, of all people?"

"Because I don't trust the effect it has on Jace, and Isabelle...I don't think she'll take kindly to having more runes on her skin?" Alec ran a hand through his already messy raven locks, sighing.

"Clary" his voice was strained. "Izzy is a Shadowhunter, in other words, she has to expect more marks on her skin. Besides, it's not exactly a bad thing if you ask me. Guys usually find her cool with the marks."

"She's dating Simon now." Clary looked at Alec pointedly, to which he chose to ignore. "Then it just means the Daylighter likes her markings."

"Simon." Clary corrected, following Alec behind as he fell onto one of the armchairs in the library. "Please, Alec?"

Another sigh. "Clary. The last time I offered myself as a test subject-"

"See, you offered!" Clary cut in, hope coloring her tone. Instead, Alec continued as if he hadn't heard her. "I almost came out to my parents that I was gay and dating a Downworlder." A grimace appeared on his lips as he recalled his most recent break-up with Magnus. "It was only sheer miracle I wasn't punished or stripped of my marks or anything. Not that it matters now, anyway."

"You guys…haven't talked?" Clary asked after a while, guilt flowing through her. Alec shook his head humorlessly. "Why would he? Besides, your pain of a boyfriend broke my phone, and I have yet to get a new one because of that."

"He's your Parabatai too." Clary shot back, earning her a small smile from Alec. "But back to the topic of your runes, find someone else."

"And I have to insist that you be the first to test the power of the runes!" Clary crossed her arms defiantly and stared down at Alec. Green eyes clashed with blue eyes for a while, and just as Clary decided to cave in to rest her already painfully strained eyes, Alec broke the intense competition, hand back to messing up black tresses as he groaned.

"Alright, fine. I give. You're as bad as Jace in the stubbornness department. What's the rune?"

"Jace!" Jace turned his head as Izzy ran up to him, her black locks swinging behind her. "Have you seen Alec around anywhere?"

"Cooped up again in the library I think." Jace sighed. "The ways of dealing with heartbreak, and he picks the library. As expected." He winced as Izzy slapped him across the arm, hard. "Shut it. He could have dealt with it worst. We should be thankful that he's buried in books than doing anything stupid. Although, it doesn't make me want to kill Magnus any less."

"Trust me, me neither." Jace resumed his walking, Izzy following behind. "I'll burn his glittery apartment down if I could, but then Alec would get upset with me and that's the last thing I need, even if it was for his sake." Izzy sighed. "The things we do for a very, scarily, calm and rationale Alec…Clary? What are you doing?"

Like a deer caught in headlights, Clary bolted upright immediately from where she had been fiddling with the door. "J…Jace, Izzy. Hi." She smiled nervously, her eyes constantly flickering back and forth between them and the door.

"Is the door more attractive than me, Clary?" Jace raised an eyebrow as he folded his arms. "And what are you doing outside Alec's room?"

"Uhm, that…" Jace's eyes widened suddenly.

"Don't tell me, you have a thing for Alec!?" Now it was Clary's turn to look shocked. "NO!" she all but yelled, before she flinched, looked nervously at the door as if it was going to slam open anything to reveal a monster or something. "Uhm, I was just looking for Alec and he wasn't in and-"

"So you have something for him!" this time, Izzy smacked her brother across the head. "Quit it, you blonde idiot! Anyway, sneaking around Alec's room isn't going to make him appear, and last I checked his room is nothing but books, his horrifying clothes and his personal items here and there, so don't worry like you think he'll burn you or something for entering his room." Clary nodded slowly as a thoughtful look crossed Izzy's face.

"On second thought, maybe he might be having something in there. Let's go check out his room!" Izzy sauntered past Jace, only to be stopped by a horrified looking Clary with a loud "NO!"

"Why not?" Izzy raised an eyebrow. "That's my brother's room, y'know."

"Yea, but uhm…like you said, it's his room so…" Clary brightened up all of a sudden. "Let's go Taki's! I'm hungry! C'mon Jace, let's go!"

"Clary…" Jace looked at her curiously. "You're hiding something from me." He walked towards her, frowning even deeper as Clary backed herself up against the door. "No…nothing. Absolutely nothing!"

"Clary…" Jace's voice was gentle, but she heard the undertones of a warning. "It can't be nothing wrong if you're sneaking outside my Parabatai's room, all guilty, and acting like this!"

"Ac…acting like what?" she straightened defensively, crossing her arms like a petulant child. "I'm just thinking in Alec's best interests of his privacy!"

"And since when have you and my brother been so close that you would defend his honor?" Izzy was now looming over her like a hawk. "Jace! Something is fishy!"

"You don't need to tell me twice." Never breaking eye contact from Clary, Jace reached for the doorknob, only for Clary to knock away his hand. "Its nothing, Jace, really!"

"This is dragging out too long, that's it!" Jace and Clary had barely time to react before a whip came whipping down, smashing into the wooden door. Shielding Clary in his arms from the flying debris, Jace looked over his shoulder furiously. "Izzy! A warning next time? You could have hurt Clary!" Izzy merely gave him a look before she snuck through the hole she had created, while Clary and Jace looked at each other.

"You alright?" Jace brushed her face tenderly. "Yea…yea…" Jace smiled, and opened his mouth…

"BY THE ANGEL!? WHAT IN RAZIEL'S NAME IS THIS!?"

Clary groaned and buried her face into Jace's chest. She was in trouble this time.

"Regression rune."

A gulp.

"Let me get this straight." Maryse was torn between being amused and furious as she adjusted the bundle of joy squirming on her lap. "You approached Alec to try the rune."

A slow nod.

"And apparently, the rune was meant to deal with bigger demons that were hard for Shadowhunters to deal with. Shrink them, to be exact."

Another nod.

"But the result was that…my son…" she took a breath. "Alec. Is. Reduced. To. Being. A. baby!?"

All eyes turned to Maryse's lap as said baby giggled happily.

"Pretty much, yes." Clary's voice was small, her gaze on her shifting feet. Maryse sighed, adjusting an armful of baby. "Do you have any idea how long this is going to last?"

"Uhm…no…?"

"So my Parabatai is going to be a baby forever!?" A look from Maryse shut Jace up. "Well…I mean…"

"Clary." Maryse took a deep breath. "As much as I appreciate that you are working hard to help us…"

"I'm sorry!" Clary cried out. "I'll take responsibility for him!"

"No, that's beside the point!" Izzy said, exasperated. "Alec can't be stuck in a baby form forever! Can't you…draw a rune to make him normal!?"

"A baby isn't suited for handling runes at this age, Izzy!" Maryse cut in. "Everyone just remain calm!"

A series of coo-ing sounds had everyone looking at Maryse's chest, where (baby) Alec had fallen asleep with a contended smile on his face.

There was a long silence. "Well." Jace spoke up after a while. "I suppose I can live with this cuteness as my Parabatai."

"Jace!" Izzy and Clary whispered-yelled at him. Maryse shook her head in amusement, standing up slowly as she held Alec in her arms. "Alright. That's enough, all of you. Let's hope Alec turns back to normal soon, and Clary…"

Clary looked up at her with an audible gulp. "…no more guinea pigs. For now."

A/N: So…Alec's volunteering to try the Fearless rune kind of stuck in my head, and then this came out. But the rune mentioned here is completely not mentioned in the Codex or anything, for the record. So anyway! Should I leave this as a one-shot or continue it? Please review, PLEASE, so I know to continue or just leave it as it is.