The Notebook

"Izuku, you're going to be late for school!"

Izuku cursed and finished up his notes. He normally wouldn't bring work home with him, but things had been crazy since the Commission fell. Villain activity had been at an all time high as society struggled to readjust and find where heroes were going to fit, so the demand for Izuku's services had been overwhelming.

Izuku was about to shove the notebook in his backpack, but stopped at the last minute. His bullies often tried to steal his backpack and look through his "nerd notebooks" and things were already suspicious enough since Ito had laid off bullying him a few weeks ago. If one of his bullies were to accidentally read his Mastermind notes...that would be bad.

"Izuku! Hurry!"

He cursed and settled for just leaving it on the desk. Mom didn't come into his room often and when she did, she respected his privacy enough to not open his notebooks. It'd be fine.

"Izuku!" Mom opened the door as Izuku shouldered his backpack. "You're going to miss the train!"

"Alright, alright, I'm going!" He kissed Mom on the cheek as he closed the door to his room again. "Love you!"

Mom smiled, "Love you too, Izuku. Have a great day at school!"

Inko didn't normally clean Izuku's room. He was a tidy enough boy and Inko firmly believed in giving children space and trust, but when she'd peeked her head in that morning, his room had been a mess. And Izuku had seemed so stressed lately! Inko didn't know if something had happened at school or if he was just worried over everything that had happened with the Commission, but either way she figured it was her duty as a mother to do something nice for her baby.

After she'd grabbed the mountain of dirty clothes from his floor, she could finally start vacuuming. She was just vacuuming by his desk when she accidentally got too close and bumped it with her hip, knocking off a notebook that had been balanced precariously on the edge. It landed open on the floor and Inko bent to pick it up and put it back. Before she closed it, she happened to glance at the page it had opened to.

...the best way to combat Mr. Brave's quirk is through a fire quirk. It's too risky to simply cut the hair, since he can still control it while it is detached. Either burn alive or….

Inko never read Izuku's diaries. She knew they were all just rambling about heroes anyway, so there was no need for her to invade his privacy that way, but this was different. This was...violent.

Inko couldn't help herself as she numbly read through the book, the vacuum running forgotten beside her. What...what had her baby gotten himself into? Why was he writing things like this? These weren't just lists of some heroes' weaknesses, they were plans to kill them, sometimes by using specific quirks. Were these people threatening her baby? They must be, Izuku would never do something like this. Or maybe they had convinced him that they were his friends and this was peer pressure like the other parents had always warned her about?

Maybe she should confront him about it. He wouldn't try to hide something like this from his mother, right? But if he really was being threatened...Inko made up her mind, put the vacuum away and walked out the door with the notebook in her purse. This was bigger than her and it was bigger than Izuku.

If her baby really had fallen in with the wrong crowd, she needed help.

Tsukauchi stared at the ceiling above his desk unseeing. If someone had asked him two years ago what the biggest change would be in Japan in the next few years, he probably would have said it would be Toshinori retiring and allowing his successor to take up the number one spot. He never would have predicted Mastermind's reign of terror and the fall of the Hero Commission.

Japan would never be the same again. Crime was at an all time high, as was vigilantism, which the police now didn't have any way to fight. What was vigilantism anyway? Doing hero work without a license? Since the Commission had been responsible for issuing licenses, that was now everyone. Was it using your quirk in public? Well, lawmakers had been quick to repeal the law prohibiting that, since that was one of the main laws that allowed the Commission to rise to power in the first place and no one wanted a repeat of that disaster.

There had already been several new hero licensing systems proposed and analysts were predicting one would be in place by the end of the year, but in the meantime, it was chaos. However the licensing system ended up, though, it was clear that daylight heroes were a thing of the past. It had become far too obvious with Mastermind's hostage situation that being popular could get you killed, so most heroes had switched to going out mostly at night and support companies had been busy changing costumes to be more practical and less flashy. Hero schools were still running, but they were training their students to go underground and had stopped emphasizing popularity. Many students had dropped out and enrollment was at an all-time low. Even UA was only going to offer one hero class next year.

But there was something else bothering him besides the general state of society.

Tsukauchi just couldn't stop thinking about the interview he'd had with Izuku Midoriya. By all accounts, the interview had been routine, just inform the family of the father's death and clear them of suspicion. It should have been an open-shut case and have done with it, but the more Tsukauchi thought about it, the more it seemed like a puzzle was falling into place.

Midoriya was quirkless, which Nedzu had said was a very real possibility for Mastermind, as hard as that was to believe. That wasn't enough to damn the boy, but it also wasn't the only piece of evidence that pointed to him. He was the right age to be Mastermind, and there were even the initials! Sure, they had no way of knowing if Mastermind's initials were I.M. or M.I. but it fit.

But then why hadn't it registered as a lie when Midoriya had said his father was alive when he left? Had he found some way to trick Tsukauchi's quirk or had someone else killed Dragon? It just didn't make any sense. It felt like there was something just out of reach nagging at him, just one peice of evidence he was missing that would make everything come together.

"Tsukauchi?" Sansa pulled him out of his voice. "There's a woman here I think you might want to talk to. I put her in interrogation room three for you."

Tsukauchi nodded and stood, stretching out his back. Oh well, he'd have to come back to his Midoriya is Mastermind theory later. There wasn't quite enough evidence to act on it yet. He grabbed a cup of coffee and almost stopped short when he opened the door to the interrogation room and saw Inko Midoriya waiting for him.

She'd obviously been crying and Sansa had apparently offered her a box of tissues because there was already a small mountain of them scattered across the table. In front of her was a plain notebook that didn't seem too suspicious on it's own, but Tsukauchi's wild theory made it seem like the most conspicuous object in the entire room.

"Mrs. Midoriya, it's a pleasure to see you again. What can I help you with?"

Inko sniffed loudly, "I-it's my son, I-izuku! I think he m-may have fallen in with the wrong crowd and...Oh Detective! I don't know what to do!"

True

Tsukauchi sat down across from her, "Why do you think that? Has he been acting strangely?"

Inko shook her head, "No, he's still the same sweet boy he always is, but…" she pushed the notebook toward him, "I found this in his room this morning."

True

Tsukauchi opened the notebook and gasped. After hours of poring over neatly written murder plans, he could recognize Mastermind's handwriting anywhere. This could be the last piece of evidence he was looking for! Unless Inko was right and Izuku had simply accidentally made friends with Mastermind somehow. Mastermind could have just asked him to hold onto the notebook for some reason.

"Mrs. Midoriya, I'm going to ask you something and I need you to be completely honest with me." Tsukauchi said. "Is this your son's handwriting?"

"Yes."

True

"Are you sure?" Tsukauchi couldn't risk being wrong about this.

"Yes, it's definitely Izuku's handwriting, why are you…"

True

Tsukauchi stood, "I need to check on a few things, Mrs. Midoriya, before I can tell you anything more, so sit tight. Just know that you did the right thing bringing this to us and we're going to help you. Is there anything we can get for you? I can have Sansa bring you a coffee if you'd like?"

Inko shook her head, "Just protect my baby."

Tsukauchi turned away so she couldn't see his face and left, already dialing Nedzu.

"And you're sure?" Nedzu asked as soon as he arrived.

Tsukauchi nodded, "It all fits, Izuku Midoriya matches everything we know about Mastermind. There was even an incident where Mrs. Midoriya was mugged a few months ago and from what the officers said, it appears her body could have been completely taken apart and reassembled by someone who looked like a bird, which could mean she was threatened by Overhaul. He is the same age, build, and height as Mastermind, not to mention his hair color, which matches some of the earliest reports we ever gathered. His quirklessness practically guarantees he was bullied, like Eri told us, so this notebook is the nail in the coffin. Mrs. Midoriya said that it's definitely her son's handwriting."

"Well then," Nedzu smiled, "this is a very good thing."

"I don't know." Tsukauchi frowned. "I have a distraught mother in the other room who is pleading with me to protect her son and instead I have to tell her that her son is one of the most infamous villains in modern history."

Nedzu thought for a moment, "Perhaps it would actually be best to hold off on that revelation…"

"What do you mean? She has a right to know..."

"Oh undoubtedly," Nedzu agreed, "but the fact is that knowing Mastermind's identity does not resolve his hostage situation in and of itself. We may have won the battle, Detective, but we have yet to win the war."

Tsukauchi sighed, "I guess I just got so caught up in the euphoria of finally knowing that I…"

"It's alright, Detective." Nedzu said pleasantly, "It happens to the best of us, but the real question is where to go from here."

"And where is that? He probably doesn't keep the murder plans on him, since he said they'd be relased automatically if he was ever arrested or killed."

"Hmmm, yes, I agree. The word automatically makes me inclined to believe that they are most likely housed in some sort of computer program, especially with how closely he's been working with La Brava recently. It's very possible their partnership goes back much farther than we'd originally thought."

Tsukauchi let out a deep breath, "Alright, so if that's the case, he'll most likely have some sort of computer that he uses for work that we can get our hands on."

Nedzu nodded, "We'll have to be cautious though. If Midoriya gets wind of what we're planning, he will disappear and find a way to punish us for getting too close." He sighed. "This is a very precarious situation."

Inko looked up as Tsukauchi and Nedzu opened the door to the interrogation room, "What's happening? Is Izuku going to be alright? Do you know who's trying to lead my baby down the wrong path?"

Tsukauchi glanced at Nedzu, "All we can say about it at this time, Mrs. Midoriya, is that your son has definitely fallen in with the wrong crowd."

Inko sobbed and Tsukauchi awkwardly rubbed circles on her back as they waited for her to calm down, "What am I going to do? He's my baby!"

"We know, Mrs. Midoriya." Nedzu said softly. "Which is why we need your help. Izuku has connections to some very powerful villains and if we aren't careful, a lot of people could get hurt."

Inko sobbed again and Tsukauchi tried to ignore the guilt he felt, "We're going to need your help, Mrs. Midoriya. Can you tell us if Izuku has his own computer? Maybe a laptop or a P.C. in his room?"

Inko nodded, "H-he has a laptop, hardly goes anywhere without it!"

"When did he get it?" Nedzu asked.

"He bought it on sale about a year and a half ago." Inko sniffed.

Tsukauchi caught Nedzu's eye. That was about when Mastermind had stopped using internet cafes.

"Mrs. Midoriya." Nedzu said. "We need you to do something for us. We need you to put this notebook back where you found it and don't tell your son that you read it or that you spoke with us. Can you do that?"

Inko looked up at them with wide eyes, "B-but, he's my son! I need to talk to him about this!"

"Mrs. Midoriya," Tsukauchi said earnestly, "if your son notices anything suspicious, a lot of people could be in danger, including you. We know that it will be difficult for you to lie to him, but it's what we need you to do to keep a lot of people safe."

Inko sniffed again, "Are you sure this is the best way?"

"We believe it is possibly the only way." Nedzu responded.

Inko nodded, "Ok, if you're sure, I'll do it for Izuku."

"There's just one more thing we need from you Mrs. Midoriya." Nedzu said. "If your son ever leaves his laptop at home, wait until you are sure he's gone, then call us immediately."

"We wouldn't ask you if it wasn't important." Tsukauchi added.

"Mom! Did you clean my room?" Izuku yelled so Mom could hear him in the kitchen.

There was a long moment before she responded, "Yes baby, I noticed you've been stressed lately, so I thought I'd do something to cheer you up!"

Izuku glanced at his desk and sighed with relief when he saw his Mastermind notebook hadn't been moved, "Thanks Mom! You're the best!"