Please stop stealing poison from my lab, guys

Sealing the lab is the wisest thing Saihara will ever do

(A/N: This story does not follow the exact lines of the characters in game because I really don't have any way to look for transcripts or copy them one by one from a playthrough as I am currently writing this offline. Please understand. OOCness (Saihara mostly) and spoilers will ensue. So don't say I didn't warn you. Also, expect swearing because Iruma. Usually I use the characters' surnames, unless they are very close to each other, i.e.: Harukawa referring to Momota as Kaito.)

After climbing the staircase to the fifth floor and visiting Shirogane's lab, Saihara had decided to wander around a little more. Spotting a door ahead, he jogged towards it.

Pushing the door open, he was greeted with a sight that looked nothing like a lab. The room contained several chairs and a desk with what seemed like scientific equipment on it. There was a fireplace at the back, and at each inner corner of the lab was a closet with a glass door. The left one was filled with what looked like books or files, while the other held neatly arranged bottles with unknown contents. Harukawa stood next to the closet in the right, with a bottle in her hands. It seemed more like a study.

"Hey, Harukawa-san. Do you have any idea whose lab this is? This doesn't look like one at all."
"I thought you were the Ultimate Detective. How have you not figured it out yet?"

Shame boiled in Saihara's gut. Spurred on by aforementioned shame and embarrassment, he hurried over to the left closet to try looking for clues on whose lab this was.

He swung the closet door open and grabbed a file from the top row. He flipped it open near the end, only to be greeted with a gruesome picture of a white haired person on the floor with a spear in his stomach and a gag on his mouth. Saihara could have picked out more details if he hadn't flipped to a previous page out of shock. Thankfully, this page was filled with words only, and he began scanning the page.

"-izumi was found half-leaning on the wall, with a wound on her head and a mask on the-"

Saihara snapped the file shut. Picking up another file from the lower rows of the closet, he found that the contents were similar. All of them were about various murders, each with varying levels of gore. This could only mean...

"...It's my lab?"

Harukawa rolled her eyes in mild annoyance. "Yes, it is. It took you that long to get it? Some detective you are."

In an attempt to ignore her words, Saihara began to inspect the right closet. This time, he didn't even need to touch the door. He caught sight of one of the vials and paled.

The entire cupboard was filled to the brim with poison.

Harukawa pulled the door open to put back the brown bottle she was holding- it read Strike-9 Poison.

It was then Saihara made a decision that would save four people from an imminent death in the near future.

I have to lock- no, seal this place up as soon as possible.

Saihara and Harukawa exited the lab, heading back down. The assasin was decent at reading people. Although not as good as Ouma, she had experience with it in her job.

"You seem panicked, Saihara."
"No, nothing's wrong. You don't have to worry about it."

Saihara was clearly paranoid about something. But what? Harukawa pondered. Was he planning to murder? That wasn't possible, right? He had guided everyone to survival in the class trials. And combined with his promise to Akamatsu, that could never happen. Although Harukawa was still curious, she decided not to push further, and headed back to the dorms.

Saihara walked towards the warehouse. Hopefully he would find duct tape and superglue inside...

Several minutes later, Saihara exited the warehouse, necessary equipment in hand. He went to the fifth floor, and he was in front of his lab in no time. Luckily, there were no people in the vicinity, so he got to work.