It was a dark and stormy night in the Last City. The poor gas lighting flickered and sputtered in the cold, merciless wind. Misshapen constructions leaned into each other and threatened to fall apart any day now, with their sorry inhabitants in too high spirits to really care very much. Mechanical birds with leering eyes watched over the mostly empty streets. All around UnLondon was a sense of bleakness, abandonment and a most desperate need for outside salvation.
Instead, what the Last City got was Grabnok The Destroyer. The portly and nervous man had materialized in the middle of the street, instantly getting soaked by the intense rain. He hurried after the closest thing to shelter he could find inside an abandoned house. The front door was missing, but at least it still had all the other doors, windows and walls. Grabnok still had the flashlight and backpack the Foundation gave him and hesitantly went about exploring the place. It reeked of mold, dampness, rust and probably worse things, but he liked to tell himself that he was used to that by now.
He soon found a crowbar hidden inside a sofa, as well as a suspicious looking part of the walls. He pried it open with the crowbar with great effort, revealing a dust and insect covered book. He blew the detritus away in a large cloud, coughing loudly and hoping he wouldn't start sneezing. Shining his flashlight onto the book, he discovered something that made little sense to him but seemed very important:

I finally figured it out. It's all a sham, the whole city. The House of Parliament knows this, they are just trying to keep us sedated and docile with the food from the vending machines and with the surveillance while they figure out a way to reach the surface without us. We have to get there first or we'll never get there. I've stopped eating the Wonderfood, and while it allows me to think straight and plan for the rebellion and escape, it's weighing heavy on my mind with withdrawal symptoms. I have been surviving on mutant animals and human corpses, I've lied and stolen, and I'll probably get turned into a Bobby or worse. But I have to do something. I'm getting closer, now that I have the maps to the hidden sections of the House of Parliament. Tomorrow, I'll organize my team into an infiltration mission, confiscate whatever technology that allowed them to create this hellhole and use it to reach the surface.

That was the last entry, or at least appeared to be so. Well, this was none of his business. He would hop out of this place sooner or later, no sense in getting involved with local politics. Even so, he found himself getting curious and kept reading the earlier entries, not noticing the surveillance drone perching on a nearby windowsill. Before he could finish reading, he heard a high-pitched whistle and all nearby speakers blaring "Police! Halt, criminal!". Grabnok reflexively froze and tried finding an escape route, when a Bobby burst into the room wielding a corroded lead pipe. Grabnok noticed a nearby mug filled with coins, and a Wonderfood vending machine. He quickly inserted the coin and directed the hose at the ground, spraying the slimy food all over it and making the Bobby fall. He then took the chance to throw a mattress out the window and jump out of it, landing on the mattress and running away with the book and maps.
After breathing heavily for quite a while and making sure he wasn't being watched, Grabnok opened the book and maps again. There was a document that said the technology used by the House of Parliament to build UnLondon was highly unstable due to the combination of several anomalies which were supposed to be in the custody of the Foundation, possibly with the help of an inside agent. The same document even hinted at what sort of scenario UnLondon was meant to prepare for, but the details were unclear because parts of the document were ripped away. Apparently, UnLondon was meant to be a last ditch attempt at preparing for some major timeline revision event in which the British Empire never existed.
He had to hold onto this, the Foundation would surely question him about it when he hopped back into containment. But how was he supposed to defend himself with only a crowbar and a flashlight in hostile territory full of surveillance until then? And what does it mean to get "turned into a Bobby"? Was that security guard one of them? He supposed he could withstand some forced training, but if there was something more to the process, he wanted no part in it. There had to be a truly safe spot somewhere in this city where he could maintain a low profile until he hopped back. Regardless, he had to keep moving or else he would be caught for certain.
The dimension hopper sneaked in alleyways, wore improvised disguises and even ventured into sewers, always holding onto his discoveries out of some very strange sense of loyalty and duty. Not knowing how long he would stay there, he held onto his rations despite the constant pitiful pleading of the Wretches. He eventually managed to craft a crude slingshot to knock out the surveillance drones temporarily and learned many useful shortcuts. He even managed to defeat a Bobby by luring it into the front of an oncoming train. But eventually he ran out of rations, and had to resort to the Wonderfood. He felt something strange inside his stomach after eating, something not quite like porridge, but pressed on. All throughout his struggle to survive, he could see a shadowy figure stalking him, but he had to rest.
Grabnok woke up with the feeling of someone poking his side with a hard, cold object. He jolted upward, reaching for the nearest weapon to try and defend himself, but it was only another Wretch with a cane. The man in filthy rags looked like someone who had been through a dozen lifetimes of pure misery packed into a few years, and yet, he was somehow giving him a yellow smile.
"You found my book. Good. I thought they would have burned it by now."
"Who are you? Why did you write that book?" he paused and then put his hands up in a defensive gesture. "I didn't steal it, I swear!"
The man in rags laughed, and strands of bloody phlegm came out of his mouth. "You may call me Leader. It's who I have been trying to be, anyways. Hasn't worked out too well, as you can see, hahahahaha."
"Right…say, is there a spot in this city where the surveillance and the security guards won't go? I need to keep a low profile for some time."
The Leader suddenly turned grim. "Not so fast. You are an outsider. That means it is still possible to get in and out of this hellhole. I ain't helping you unless you help me. You are gonna bring me with you and tell your surface friends all about what happens here everyday so I can free this city, got it?"
Grabnok swallowed hard and began to sweat. He was a horrible liar. "S-s-s-sure thing, Leader! I got some friends in very high places¹ They'll uh…have everything under control in no time, promise!" he offered a nervous handshake, which Leader returned.
"Excellent. We need to get to the outskirts. Reality is mostly falling apart there, but there is one spot that they don't know about which is safe. Follow me."
As they ventured further and further, the less they saw guards and drones. The gas lighting became brighter and more vivid, the air and streets cleaner, and even plants grew here and there. They eventually reached a building that almost seemed like a genuine Victorian house.
"What..how…did you?" blurted out Grabnok.
"I don't know much more than you, but I'll be damned if I let anyone know about this, you hear?" Leader snarled. "Come inside, there's tea."
Once they entered the modest but comparatively wonderful house, Leader shared his other plans and notes with Grabnok.
"For years I suspected they were lying to us, but I didn't do anything about it. The others were too sedated and hypnotized by the food and the constant messages to do much better. To this day, I still don't know how I managed to wake up from all of that, or even get a few people to join my cause. But as my luck would have, they were caught and turned into Bobbies, while I ran away and continued the mission."
"The security guards are the Bobbies, right? How do they turn you into one of them?"
Leader shuddered. "I don't know, and I honestly don't want to." He suddenly beamed with exalted joy. "But now I have you here, and it's all gonna pay off, I just know it!"
Leader's smile dissolved as lightning struck his house, making everything dark. Something lit up inside Grabnok's stomach with the same color as the eyes of the surveillance drones, and he vomited it back up. The spherical thing squirmed on the ground before assuming the form of a drone and sealing the fate of both of them with its glowing gaze.
Leader burst into a mad dash to try and destroy the drone but failed, and Grabnok was too busy vomiting still. When the drone flew away, Leader turned stood still for a few moments, unleashed a shriek of defeat and lunged at Grabnok, ready to kill the outsider with his bare hands. Before he could land a killing blow with a brick, Grabnok hopped outside of UnLondon, along with his backpack full Leader's notes and everything else. He tried to escape, but soon enough a dozen Bobbies were at his door and he was escorted to Bryson's Home For The Poor.
When Grabnok returned to containment, he shared the secrets he had discovered with the Foundation and told the story of what happened. He was asked if he would like a reward for his cooperation. He simply said:
"Some decent porridge, and a bright and sunny day."