She did not thank Delgato for the ride home, nor did she greet the marmot sitting at the front desk of her apartment building. There was no time for either. She simply raced through the doors and up the staircase, not bothering to wait for the elevator. Her shoulder and chest protested a little, but she ignored the pain as she fiddled with the keys in her pocket as she arrived at her door. Her paws were shaking, making her miss the keyhole on the first try.

“Come on!” she cursed before finally unlocking her door. She dumped her tote bag on the floor by the door, walking in and slamming it behind her. 

Her eyes scanned up and down frantically at the entryway of her apartment. If there was something obvious, she would have caught it before, so now she needed to look for things hidden. She had no doubt that the ZBI weren’t above snooping around her place without a warrant, and Nick would have assumed the same. 

“If I were Nick, where would I have hidden a message?” she thought aloud. 

She began with his closet. Nick kept an extensive collection of tacky shirts hung and ready for any occasion. Judy would often mock him for his horrible taste in fashion since many of his shirts had odd patterns and clashing colors. She pulled each one off the hanger and dug through their breast pockets, tossing them to the floor before reaching for the next one. 

She furrowed her brow as she thought of where else to look. Perhaps he hid something in the bathroom for her to find during her morning routine that she overlooked. She went into their bathroom and opened up the mirror, tearing all the various products and medicines off of the shelves and onto the floor. She checked the window, the shower, the fur-drier, and even the toilet, with no luck. 

After she was satisfied she had cleared the room completely, she moved on to the bedroom and turned the place upside down. There were no notes left on the dresser or on her alarm clock. Her dresser was clean too, so she riffled through the bed sheets for good measure, leaving a proper mess in her wake. 

“Come on, Slick, talk to me,” she murmured, making her way into the kitchen. 

Their fridge had plenty of food going bad in it, and the pantry was cluttered too. She took a little extra time going through the carrots in the produce drawer, but she still found nothing. In frustration, she began pulling cutlery and kitchenware out of the drawers and onto the kitchen counter. She felt a little foolish for thinking that Nick would leave her a message in her salad spinner, but at a certain point it felt satisfying to be making noise. 

She was off track now, so she stood in the kitchen and thought a bit more carefully. He’d leave it somewhere for her to find. When they first met, he read her like a book after their encounter at that ice cream shop. After growing closer, becoming partners, and living together, Nick knew her better than she knew herself. So where would she look?

She went back into the bedroom and opened the cupboard that contained all of her stuffed animals from home. Most of them were rabbits, but there was one small fox among them that she observed closely. No luck. She fidgeted inside her desk and fished out her old carrot pen, the same tool she used to hustle him into helping her with her first case. She hit play but only heard static. 

She went back into the living room and reached up to the bookshelf beside the sofa and pulled out a wide canvas book. She insisted on making this photo album for the two of them, despite Nick’s reluctance to spend money on something technology could do, he claimed, better. It was important to her because for one, they never really took the time to thumb through old photos on their phones. Also, she liked having something physical to flip through together. 

Judy opened it up and immediately began scanning the pages for any notes or signs that Nick had been there. The first couple of photos featured a few silly selfies of Nick with Judy caught unsuspecting in the background. The next few were photos that Nick took during their first day in their new apartment together, when Judy decided not to include the pictures Nick took of her rear. The next few were photos that she took, one selfie of the two of them at the park caught her eye. Nick promised he wasn’t going to pull the sneak-a-kiss maneuver when she took it, saying that it was an old trick that was too predictable. The long-tongued liar had buried his lips into her cheek the moment she took it, getting a cheeky smile from both of them. 

Judy felt something warm crawl down her cheek. She was surprised to find her eyes were wet when she reached up and rubbed them with her forearm. She spent more time looking at pictures than she would have liked. After a certain point, she wasn’t looking for clues anymore. Judy sighed and flipped through the rest of the pages quickly. After she was satisfied that there was nothing in there for her to find, she placed the book aside and looked up at the ceiling. 

It was always easy to tell whenever she caught Nick off guard. He had a practiced, well-rehearsed face he wore whenever he was pulling a con or being even a little bit sneaky. In a lot of ways, she loved that smile despite it being so frustrating sometimes. It meant she was in for a surprise, be it pleasant or annoying, and having someone predictable would probably bore her in the long run. But whenever she had the upper hand, his eyes would widen and he would bumble his words, trying desperately to talk his way out. That look of shock was on his face right before he shot her. She could still vaguely see it, his face blurred in an afterimage from the flash of his pistol. 

She rubbed her chest, her ribcage still aching in pain. She had forgotten to pick up any painkillers from the hospital before she left, so she would have to make due with whatever she had in her medicine cabinet. She slowly rolled up off the sofa and trudged back into the bathroom that now looked like a tornado had swept through. She found some ibuprofen and pulled out her glass, holding it under the sink. 

Instead of a steady stream of water, the faucet sputtered and spat water and air violently. 

“Eugh,” Judy groaned, fiddling with the faucet. The water continued to sputter and cough like a sick child until she only used the cold water. She filled her glass and popped a few pills, groaning with the knowledge that they would do little to mend her aching ribs and shoulder. 

Shutting off the water, Judy eyed her sink with a furrowed brow. She tested the cold water once again; it worked fine. The hot water, on the other hand, blew air and water sporadically before it stopped altogether. With a raised eyebrow, Judy turned around and hopped into the shower. She stood out of the way of the water and turned it to its hottest setting. The water flowed evenly at first, then coughed violently just like the sink had before running completely dry. 

“What the . . .” she wondered. The water heater was in a utility closet beside the kitchen. It was about twice her height and about as old as her appartment was. She opened the closet and observed it closely. There weren’t many buttons or levers on it, so if it was broken there were only a few things she could do to try to fix it. Off to one side, she noticed a valve labeled ‘Master Shutoff’. Judy pulled the lever up flush with the piping, and she heard the satisfying sound of water bubbling up through the plumbing. She tested the hot water in the kitchen sink, and now it worked just fine. 

I definitely took a shower Tuesday morning, Judy realized. She remembered showering after the one night that week she had spent at home since Nick’s disappearance, so someone had shut the valve off since then. Judy ran over to the front door and inspected the doorknob for any signs of a forced entry. She did not find anything out of the ordinary, so it must have been someone with a key to her apartment.

“Nick,” she whispered and looked back at the hot water heater. “What are you trying to tell me?”

Spitz, she remembered. There were water heaters in the refrigerator at Spitz’s house! Terrence had paid off the capybara some big money for scavenged water heaters, which he must have delivered using his customized truck that wasn’t starting. Terrence also paid off a street dealer named Willie for some chlorine off the grid. Chlorine he used at their hideout to build a bomb. 

Judy inspected the water heater more closely, looking for a warning label of some kind. Anything that held pressure would normally come with some obvious warning sign for liability purposes. She creeped deeper into the utility closet and looked up and down on the opposite side. Near the top of the tank, she found the warning label, along with an envelope taped to it. 

“Bingo!” Judy said and pulled the envelope from the side of the tank. The front of the envelope was labeled with black marker with Nick’s writing. 

Toot Toot, it read. 

She practically tore the envelope up like a kid on Christmas. She stepped back into the light of the kitchen and pulled out a thin slip of paper. It was a boarding pass for a train ride from Downtown to Bunnyburrow. A part of Judy was elated that she found something Nick left for her, but another part was worried about what he was telling her. 

A ticket home could be his way of telling her to get out of the city while she could. Terrence had pulled a similar stunt, making sure his son was out of town before bombs went off. But Nick would know how stupid he would need to be if he thought she was going to leave the city at a time like this. 

She dug around the envelope, but there was nothing else in it. The ticket to Bunnyburrow was all there was. She slid back into the utility closet, looking for any other sign of Nick. While she did not find any more clues, she did find the warning label she was looking for originally. Her water heater was rated for 150 pounds per square inch of pressure. 

Judy ran over to the counter where her phone rested and opened up Zoogle, typing in ‘water heater pressure rupture’. The first link that came up was a video from some reality tv show’s website. The video was called ‘exploding water heater’. Judy clicked on the link and watched as two energetic tv hosts walked her through their test to push a water heater to its breaking point. 

“Basically, a water heater is a giant pressure tank,” the first one explained, pointing at their water heater they were testing. “There are many safety precautions on it that we’re going to have to break in order to test out our theory. This one here is an emergency pressure valve that will slowly leak pressure once it gets too high. That way there’s no catastrophic failure.”

“But we’re going to plug that up,” the other host said with a wicked smile. “Along with the backup valve as well. Then we’re going to pump this thing full of pressure until it goes boom!”

Judy skipped ahead a few minutes as they prepped the tank and began pumping it full of compressed air. The pressure gauge built up higher and higher, venturing into the red on the dial. The hosts stood behind a blast shield and gave the camera a thumbs up. Most shows like this one were designed to get kids interested in science, and what was cooler than blowing things up?

Judy gasped as the bottom of the tank gave way and exploded with tremendous force. The tank itself flew upwards like a rocket, and the area around the tank erupted with water vapor spewing everywhere. The cloud of water vapor covered nearly 50 feet instantly in all directions before blowing away in the wind. 

“Don’t worry, kids at home,” one host said in conclusion. “The water heater in your own home is designed with these safety measures to make sure this doesn’t happen, and there’s no way the water pressure in your own home could build up so high.”

“Also,” the other host chimed in, “this tank is made thick steel. It would take a lot to rupture this from the outside. So there’s no reason to worry about your water heater unless it’s ancient. Just be careful to make sure your water heater’s release valves are working properly.”

Judy rewound the video back to the explosion and watched it a few more times. Her eyes were drawn to the cloud of steam that spewed in all directions after the blast. The tank had been full of water when it exploded, but what if it had been filled with something else? Something poisonous, perhaps. 

“That’s it!” Judy realized. "The water heaters are the bombs!" If they filled one full of Nighthowler serum and built the pressure up enough in the tanks, then the resulting explosion would infect anyone standing nearby. The cloud of vapor would drift on to infect even more mammals. All they needed was to pressurize the tank and rupture it when the time came. 

“But why the train ticket?” she asked herself. There was something she was missing about their plan that Nick was trying to tell her still. Knowing about the bombs might be useful, but it did not tell her where they were. The ZPD and ZBI would undoubtedly be looking at public events or highly populated areas as potential targets. 

They could blow up the bomb on a train, perhaps. That would cause untold amounts of panic and violence contained in such a confined space. But Terrence had Spitz scavenging for weeks collecting water heaters, and that plan only needed one or two. Also, that idea did not seem big enough for Pumar. From the way Pumar described it to her, it sounded like they planned to cover the whole city with Nighthowler toxin. The coming fire, he said. 

Judy looked over the train ticket in her paw and noted nothing odd about it. Savanna Central to Bunnyburrow, the same line she took whenever she visited home. It was also the same train she took when she first arrived in the city years before. She remembered being entranced by the views of the city from each district. It really made her first time in the city something wondrous to behold.

Judy dropped the ticket and her eyes widened. She jumped up and bounded out her apartment door. She quickly went back down the stairs, noting the pain in her chest resurfacing as she did so. She landed on the first floor and went to the mammal sitting at the front desk of her apartment building. The marmot looked surprised and concerned by her speed and urgency as she spoke. 

“I need a map of the subway lines!” she said frantically. 

“Oh! Uh . . . I only have them for large mammals right now,” the marmot said after digging through her desk. The poor creature was trying her best to be helpful.

“That’s fine!” Judy said, anxiously tapping her paws on the desk. The marmot lifted the map that was as tall as Judy was over the desk and plopped it down. Judy wasted no time hoisting it up over her shoulder, running back up the stairs with it. 

The unfolded map took up most of the floor space in her living room. The map had details like addresses of each subway stop and the other transit lines, as well as various monuments and sightseeing opportunities for the tourists. She pulled out a marker and began finding the spots in the city she knew Pumar’s team had been. 

“The storage house by the docks . . .” she started and circled the spot where they first found the black car and raided a storage business. She moved on towards Downtown. “The motorcycle chase . . .” Judy circled the spot where she first ran into Skye, noting it followed a subway line that led into the natural history museum. “The Rainforest District . . .” she continued. She circled the exact spot her T.U.S.K. raid took place. After she had all of them circled, she took a step back and observed the map from the top of her sofa. 

“. . . sweet cheese and crackers,” she whispered. She saw it immediately. Each of these spots were right next to the train line to Bunnyburrow. That same train she took when she first entered Zootopia snaked its way around the entire city, traveling through each district before ending up in the center of Savanna Central. She thought back to Nick’s message he tapped to the warning label. Toot toot

They’re going to hijack a train! she realized. Judy pulled out her phone and hit Clawhauser’s number as quickly as her thumbs could move. It rang only once before the dutiful cheetah picked up. 

“Hopps,” he said anxiously. “Are you alright? Delgato told me the chief put you out on leave and took your badge!”

“I’m fine, Clawhauser. I need you to patch me through to Chief. It’s important.” 

“Right now?” he asked her in surprise. 

“Yes! I think I know where they are!” she shouted. 

“Alright then, patching you through.” The line went static for a moment before it began ringing again. Judy’s foot was furiously tapping on the couch cushion as she waited for the chief to pick up. 

“Bogo here, make it quick. Things are moving here.” Chief Bogo said. 

“Chief, it’s Hopps. I think I know what they’re planning,” she began. “The water heaters from the Spitz murder, Terrence is going to rig those up as bombs by filling them with Nighthowler toxin and pressurizing them.”

“Water heaters?” Bogo wondered. “Even if they built the pressure up in one of those, they’d still need a way to detonate them.”

“That’s what the chlorine bombs are for. A smaller charge, like the one they booby-trapped their hideout with in the Rainforest District, would be just enough to rupture the tank and cause the whole thing to blow,” Judy explained. 

“So that’s what the chlorine is for, then,” Bogo agreed. 

“Exactly.”

“This is good, Hopps, but we’ve got something more pressing right now.”

“What do you mean more pressing?” Judy asked. She held her breath for a moment, fearing she was too late. 

“We got a hit on a possible match for Pumar in Tundratown. Traffic cameras picked him up by the port; we think he might be making a break for it,” Bogo explained. “I’m sending four units up there now, with everyone else on standby.”

“The port?” Judy repeated and looked down at her map. The harbor in Tundratown was way out in the open, and nowhere near the Bunnyburrow line. Pumar would never risk going out in the open. “I don’t think it’s him, Chief.”

“Oh? Do you have an idea of where they are, then? Your water heater theory is plausible, but how does that help us find them? I can caution all officers on duty to keep an eye out, but you can’t exactly sneak a water heater into a public place inconspicuously.”

“Sir,” Judy said calmly. “I don’t think they’ll be sneaking bombs anywhere. I think they’ll use the train.”

“The train? What makes you say that?” Bogo asked.

“Each location we’ve found them at so far is right along the Bunnyburrow line. That line snakes all the way around the city before ending at Savanna Central, and it stays above ground the whole way. I think they’re going to hijack a train and dump bombs out the windows as they go along until they reach Savanna Central Station and blow the rest up all at once!” 

Bogo went silent for a moment as he contemplated her theory. “Do you have anything more than just their recent locations? I can’t shut down train traffic unless I have something firmer.”

“Nick left me a message, Chief. He left me a train ticket taped to the water heater,” she explained. 

“In your apartment? Hopps, if he left you a train ticket going out of town, I think he’s telling you to get out while you can. Savage tells me he did the same for his mother,” Bogo argued. 

“Do you think I would ever take a ticket and run