Prison Pandemonium

Peracetic

Throughout the fifth day, Mara continued to kill. Hell, some died without her directly killing them just from wounds they had received from the explosion.
Roach & Skinner scavenged for resources, and our main group of characters slept off and on, relieved that the action within the prison had dwindled down from the aftershock of the explosion.
Roman was already plotting what he could do next, and fortunately, an answer came to him in the form of a dream.
He was taken back to freshman year science class in high school, where they had been learning about acids and what not to mix together. Roman was always attentive, considering he always wanted to be a scientist, but the dumb football meatheads didn't listen to a word he said. If they had, they could have avoided the horrific fate that awaited them.
They had been doing a lab where they were instructed to mix certain things together. The main leader of the meathead friend group was named Royal, and he had been the worst of them all. They were all goofing off, and Royal decided to pour two random things into a beaker just to piss off the teacher.
Unbeknownst to Royal, there was a beaker of vinegar right next to him. He picked this one, thinking it was water. He grabbed a bottle of hydrogen peroxide and poured it into the vinegar, which caused the glass beaker to explode, sending this toxic substance directly into Royal's face. He screamed as the concoction he had made began melting his flesh, and he breathed in the toxins, along with his friends.
The teacher had made everyone quickly evacuate, and the emergency room was called. They were taken away, but unfortunately Royal did not make it.
What Royal had made was none other than "Peracetic Acid", which Roman had called "parasitic acid" considering it was like a skin eating parasite. It was formed when you mixed vinegar and hydrogen peroxide.
Royal didn't stand a chance against this acid considering how damned corrosive it was. The lab area it had exploded on had melted away, and the lab had been closed down. Even people who hadn't been in the lab and walked near it accidentally inhaled the fumes and got horrifically sick. The area was eventually closed off because of this.
Roman knew what he could do. He would have various of his new found allies hunt for plenty of vinegar and hydrogen peroxide, and then they could form the acid and pour it onto Mara, subsequently dissolving her metal frame and destroying her. The only issue was that it would have to be when she didn't expect it, because if she knew it was coming, she would put up her force field in retaliation.
On the morning of day six, Roman informed the others of his plan. They were cautious of course, considering the week was almost over and they would supposedly be let go. Roman quickly quelled these statements by reminding them that Mara would ensure to kill them by then. They agreed to the plan. There's something truly poetic about using "parasitic" acid to kill a parasite like Mara, nothing more than a robot made to kill.