Dr. Lila tells Azzy that she needs her to investigate a room that suddenly opened in The Unnamed Core Area. Finding nothing suspicious about that, she stumbles upon the entrance to the True Lab and peeks inside. As she gets further in, Puppy pops up and attacks a control panel on the wall, slipping out before the door closes. This causes the power for the True Lab to cut out, trapping Azzy inside with only her phone for light. Meanwhile, Puppy begins to enact his plan, leaving Dr. Lila's things ouside the True Lab for her to find and going to the rest of the Underground to gather Azzy's friends together. Azzy's left wandering the lab for a while, with Kokoro suggesting they call Dr. Lila for help. No one picks up, so they look for a way to restore some power to the area. After stumbling around in the dark for a while, they find an old generator, turning it on and restoring some light the lab. Unfortunately, the door still isn't working, so they decide to venture further in figure out another way to open it.
Along the way, Azzy reads notes and research entries, learning more about the experiments carried out in the True Lab. Eventually she finds another door and control panel, with an "Open All Doors" option after messing with it a bit. What follows is the sound of several doors opening mechanically, all but the door at the entrance, to her frustration. Kokoro brings up the possibility there could be something in one of the other open rooms. Checking them one-by-one, they find nothing except some sticky residue on the floor and walls. The last room they check has an Amalgamate hanging from the ceiling, which starts a battle after being startled. Instinctively, Azzy flees, unsure of how to deal with it. Running further into the lab, a bigger Amalgamate blocks the way. It stares at Azzy with DETERMINATION dripping from its body before chasing her out of the room. After hiding in one of the unoccupied rooms, Azzy attempts to call Dr. Lila again, anxiously waiting while the phone rings.
Earlier:
Dr. Lila wakes up, thinking she'd overworked herself with Ariatto's repairs, but panics after finding her phone and key missing. Hurredly, she checks her cameras, only to see Azzy entering the recently unlocked True Lab. With little time to spare, she rushes over to stop Azzy before anything bad can happen. By the time she get there, the door's already closed. Strangely, her phone and key are already there, so she takes them before trying to open the True Lab. The panel for the key sparks and fizzles out when she tries it, increasing her panic as it'd obviously been tampered with. With no other choice, she runs back to her lab to get Ariatto working again to break open the door. Just then, she receives a call from Azzy.
Relieved, but also confused, Dr. Lila questions her about how she got into the True Lab before being interrupted by Azzy frantically describing her situation of hiding from the Amalgamates. Dr. Lila manages to calm her down and explains that she just needs to calm the Amalgamates down too. She instructs Azzy over the phone where they're likely to be and what to do to make them settle down, all while working as fast as she can to repair Ariatto. After dealing with the previous two she found, Azzy returns to the room she had been chased out of, finding broken cases. Dr. Lila admits that they held Anti-SOULs, early experiments she wasn't proud of and locked up to prevent them from hurting anyone, suggesting that it'd be best to avoid them if possible. After dealing with the other Amalgamates and some optional fights with the Anti-SOULs, Dr. Lila comes crashing through the True Lab entrance with Ariatto. They wrap things up by taking the Amalgamates back to their rooms and trapping the Anti-SOULs to be dealt with later. Glad to have the whole ordeal over, Dr. Lila escorts Azzy out of the True Lab with a question or two needing to be answered.
It all leads up to this.