After discovering the body, the Monokubs arrive to hand out Monokuma File 3, which details the time and cause of death. A discussion then ensues about performing another ritual, and a group of students leave the room. Since Kaito still isn't feeling up to the task, this investigation will be conducted with Maki.
Ultimate Artist Lab
Start by speaking to the remaining students in the room (Miu, Tsumugi, Gonta, and Maki). Tsumugi provides a Truth Bullet, Tsumugi's Account, as she details that Angie only let members of the "student council" into her lab while she was working. Since Tenko was the only member of the student council who turned against Angie, most of the suspicion falls on her. Maki confirms with Shuichi that the Art Lab's Front Door was locked before Kokichi forced it open, meaning that someone must have locked the door from inside.
Examine the Art Lab's Back Door for another clue; while the door remains locked, Maki notices a trace of gold on the sliding lock. Shuichi also notices that the door doesn't take much effort to lock, making it a potentially important clue. Maki then draws attention to Kokichi's Lockpicking, as he displayed the skill to open the locked door and appeared with suspiciously convenient timing. Finally, examine the body to approach it.
Near the body, examine the Effigies Hung Upside-down. Anyone could have gotten rope from the Warehouse to hang the wax dolls up, but their peculiarity is hard to ignore. Examine the Gold Leaf Katana that has been used to stab one of the dolls. Upon closer examination, it appears to be the murder weapon, but it isn't the most effective weapon due to its age. Could it have been used for its proximity or length? Examine the Necronomicon on the floor near the body to take a closer look at its pages. Examine the body and the pair will notice that the Forehead Injury is a deep wound, though it isn't bleeding much. Maki will then find some Bloody Duct Tape nearby, though its purpose is still a mystery. Examine the pool of blood by the body to conclude the investigation here and move on to the next location.
Ultimate Anthropologist Lab
Upon entering, examine the exhibit case where the katana should be. Only its sheath remains, confirming that this is where the murder weapon came from. Kokichi then enters to tell the pair about the seance, which is detailed in the book The Caged Child. Follow Kokichi to the empty classroom in the center of the hall, where the seance is being conducted.
Empty Room - Middle
After the scene, Monokuma File 3 will be updated. There is now another mystery to uncover. After another scene, the group discovers Keebo's Flashlight Function. Speak to Tsumugi, Maki, Himiko, Gonta, Keebo, Korekiyo, Miu, and Kokichi. Korekiyo recounts the Sound During Seance, though its origin is still unclear. Examine the lit candle and the Dog Statue, which is remarkably heavy and likely impossible to move with the strength of one person alone.
Examine the White Sheet, which is found to have a bloodstain on it without any visible tears, indicating that the victim was stabbed while underneath the cloth, but not through it. Examine the Magic Circle Korekiyo Drew to find that it's been ruined by the students' footsteps. Examine the Hole in the Corner, located at the back-left of the room. Maki notices that something has dropped through the hole to the floor below, so Shuichi agrees to investigate it later.
Finally, examine the body to approach it. Examine the Iron Cage to find another bloodstain, indicating that the stabbing took place while the victim was still underneath the cage. Examine the Marker Stone to the left of the body, which was used during the seance to mark the location of the subject. Examine the Loose Floorboard underneath the body; Shuichi notes that it must have come loose during the seance, but its weight would make this difficult unless the action was performed intentionally. Examine the body and Shuichi and Maki will discuss the victim's Last Moments; was death instant, or was the silence after the stabbing by choice? After investigating everything here, Shuichi and Maki will continue their investigation by going underneath the floorboards.
Under the floorboards, examine the cut Crosspiece Under the Floor, which seems to line up with the crooked floorboard above and appears to have been cut intentionally. Turn the camera to the right and examine the hole in the wall, which could have been a way for the perpetrator to move from room to room without using the hallway. Examine large bloodstain in the foreground, then the Dried Blood Under the Floor, in the form of a small bloodstain in the background. Finally, turn the camera left and examine the Sickle Under the Floor, which appears to be a murder weapon. Exit the room for a scene and another Truth Bullet, after which it is time to head to the trial grounds.