I crossed Daniel's scent wall and resumed my patrol, going at a slower pace after burning so much energy. It was almost a relief when the sun finally set and the darkness dropped around me like a cloak.

My anger had faded, but I still felt slightly wound up for some reason. I rubbed my temples as I jogged, noting that my headache hadn't faded, which was odd.

The scenery farther ahead hazed slightly for half a second, from the ground up, like a heat haze above a road on a hot day. I slid to an abrupt stop, baring my teeth at the unexpected event. Heat hazes did not happen in a cool forest at night. What the hell was that?

I took a cautious sniff but didn't smell any gases or anything else that seemed out of place. Not all gases had odors though, and as a zombie, I might not notice a drop in oxygen levels.

I tilted my head, I stared at that spot and listened hard, although I didn't see anything out of the ordinary. Nor did I hear anything unusual, such as an underground gas pocket hissing with its rapid escape.

Did I imagine it? The haze had only been present for a split second. If I'd blinked, I could have missed it. If there had been any fog rising, I wouldn't have noticed the faint change.

As I edged closer to the spot, I let my instincts come forward in case they could pick something up. They had strengthened when the sun set, but they seemed more restless than usual. I tested the air again but remained clueless as to what had my instincts unsettled.

I glanced back but didn't see any fog or anything that looked like a gas cloud. Admittedly, I was in a forest; sometimes strange things happened among the dense trees, particularly around rotting stumps.

My instincts stirred restlessly, as if tipped off by something. The foliage hindered my sight as I continued scanning the forest around me. With a faint frown, I wondered if something could be following me. It didn't explain the odd haze, but it could explain why my instincts were so high.

I had been jogging openly along the path, so anything could have been tracking me. I rarely made the mistake of traveling in such an open fashion along a deer trail, and I was once more reminded I was a Nightstalker.

With that in mind, I eased into the foliage and went into full stalker mode. I circled around and doubled back, trying to find what had my instincts on edge or perhaps catch another glimpse of that haze and figure out the source.

Nothing.

I climbed up a tree and watched for a few minutes to ensure nothing was following my scent. Almost obsessed, I circled the area a dozen times, yet still came up empty. Nothing seemed to be trailing behind me, nor could I spot another trace of that haze.

With a mental shake, I dropped to the ground and resumed my patrol, opting to remain in stealth mode. If something happened here on my next lap, I would note the area and have Daniel check it during the day. Until then, I would put it down as a false alarm. I was almost tempted to believe I imagined it, but the way my instincts were behaving prevented me from dismissing it.

My actions might have been a bit paranoid, but I broke my scent trail several times in case someone was trailing me at a great distance. I kept my eyes open, although none of the various animals I saw seemed to think anything was wrong. Unless they caught my scent, they went about their lives as they normally did.

No alarm calls from squirrels or other creatures came from behind me. Even the regular zombies were acting as they always had. I took a few minutes to hunt down a rabbit, hoping it'd help me settle down. It was barely after midnight, so I left the carcass for the scavengers.

Despite hunting and breaking my trail, my elevated instincts left me feeling on edge and restless, which was a stark contrast to the quiet night. I shook myself off and relentlessly scanned the area again, but I didn't see anything out of place. My instincts hadn't strengthened or shifted regardless of where I was or which direction I faced, so I had no clues to go on.

About half a patrol lap later, I encountered the haze again, only this time, it rose up around me. I whirled around with a snarl and tested the air, but it was already gone. My eyes scoured the ground, but I was certain there was no way so much gas could have escaped at the same time, even if I had been in a swampy area.

There were no odd scents, nothing was near me, and my breathing didn't seem to be affected by any potential gases. The haze had only lasted a second, but I had definitely not imagined it. On top of that, the haze had been strong enough to obscure my view of the trees around me this time.

Narrowing my eyes, I backed up along the exact path I had been on, then came forward like I had the last time. The haze didn't reappear.

I moved to the side and examined the area. Something wasn't lining up. The way the haze had occurred so fast made me wonder if it had actually been my sight and not something around me.

But zombies didn't get sick... Was there any condition out there capable of causing a second-long haze across my sight? My instincts were growing increasingly unsettled, although that was partially because they were stirring in response to my own unease.

A slight tremor passed through my muscles, and I immediately narrowed my eyes at the unpleasant feeling. Could I actually be getting sick? Was it possible I wasn't dealing with an external event, but an internal foe?

I'd never heard of a zombie getting sick, so the thought hadn't occurred to me until now. I focused on my body, analyzing everything. My headache was still present and had gotten a bit worse. There was a very faint ache in my muscles, although I could very easily blow that off as the aftereffects of my demolition derby with the trees.

I felt slightly off, but I had attributed that to how my instincts were reacting. Had I been human, I might have thought I was coming down with something. I lowered my nose to my shoulder and took a deep breath but didn't detect any hint of illness.

With a sigh, I continued my patrol, going at a much more leisurely pace. Hopefully, I would get over it quickly. The last thing I needed was Nina thinking she had discovered the first-ever case of an illness in a zombie. I hope Nicky's insanity isn't contagious, because if it is, I'm screwed.

I paused in the trees and watched a normal zombie meander down the middle of the road. As far as I could tell, it wasn't acting oddly. Then again, it was a mindless zombie, so there was no way to tell if it had a headache or sore muscles.

I had been one of the originals, and it had taken the virus three months to appear after the flu shot. If the zombie virus itself had another internal clock with more changes scheduled down the road, I would be one of the first to find out. There was no way to tell if this mindless zombie was an original or not, so I kept going.

I paused as my vision wavered again, blurring everything in front of me into an impermeable haze for a couple of seconds. These events were happening more often and lasting longer. At this point, the haze also forced me to stop moving since I couldn't see the path in front of me until my vision cleared. My head pounded unpleasantly as my headache worsened.

With my sight back, I resumed my swift walk, not trusting a faster pace. All my muscles ached like I was running a high fever, but when I put my hand against my forehead, it didn't feel noticeably warmer.

The eastern sky began to lighten, only a couple of hours away from sunrise. Another tremor ran through my muscles, also lasting longer than the previous ones.

I was already on the road heading back toward the gate, although my progress was noticeably slower than before. When I rounded the corner and saw the gate, I put my sunglasses on and resigned myself to what I had to do.

All my symptoms were getting worse. Something was obviously not right, and at this point, it concerned me. As much as I hated to admit it, there was only one person here who might be able to figure out what was going on. I didn't like it, but things weren't getting better. In fact, my symptoms were progressively getting worse. If my control came into question, someone had to be aware that I might become a potential threat.

I walked through the gate and tossed the radio to the guard above. The kitchen staff weren't even up yet, proof that I was back earlier than usual. My vision hazed over, and I took a deep breath and kept my strides steady until my sight cleared two seconds later.

I entered the secondary building and continued down the hallway. Grimacing at what I was about to do, I knocked on Nina's door three times and waited. I heard shuffling as she got out of bed and approached the door. The door opened to reveal a sleepy-looking Nina in a housecoat.

She blinked in surprise when she saw it was me. "Trinity, is everything all right?"

"Nina, I'm sorry to disturb your rest, but have you ever heard of zombies getting sick?"

"No, why?"

Here we go... I sighed and said, "Because something isn't right."

She looked confused and rubbed her eyes to clear them. "What do you mean?"

I hated admitting any weakness, but there was no way around it. "I feel like I'm coming down with an illness or something. My vision is occasionally wavering, and my muscles are trembling intermittently, although I don't feel any weaker."

She frowned in concern. "Give me a minute to radio Daniel, then I'll take you to the lab to check your blood pressure and vital signs."

I waited in the hall as she disappeared into her room. I heard the click and faint buzz of a radio.

"Daniel? Could you please meet me in the lab?" I noticed she didn't use the word "over" like the radio attendant had told me to do.

"Sure. I'll be there in a couple of minutes."

My instincts were only just starting to fade, so I was surprised he was out and about when it was technically still nighttime. Although, now that I thought about it, I was able to move around during the day, so it made sense that he could be active at night if he chose. I wore sunglasses, and he'd be able to use bright flashlights as we both defied the limits that the virus tried to place on us.

Nina came back, looking more awake and now properly dressed. "Sorry, but if you have any problems with control, it's better if Daniel is nearby."

I nodded and walked beside her down the hallway. As much as I didn't want the higher-ranking zombie around during a time of potential weakness, I understood her worry. No Stronghold wanted a feral Nightstalker loose within its walls.

She opened the door that led down to the lab. "When did you start noticing the symptoms?"

"The first time my vision went hazy was shortly after midnight."

I paused on a step and shook my head fiercely as my vision disappeared momentarily. When I could see, Nina was gazing back at me with a concerned expression.

I exhaled gustily. "And it just happened again. It's happening more often, and it's lasting longer each time."

"Let's get you downstairs and sitting down. Are you dizzy at all?" Nina asked.

"No." If it hadn't been for the headache and aching muscles, I would have felt normal.

I walked beside her as we went down the hall and into what resembled an oversized examination room.

"Please take a seat." Nina gestured toward a chair beside a counter.

I reluctantly sat down and watched as she gathered a stethoscope, blood pressure band, and some other things in her arms. I may have come here on my own power, but I still didn't like admitting that I may need help if I got too sick.

As Nina put the blood pressure cuff on and started to pump it up, I heard footsteps quickly approaching. I looked over as Daniel came in. He would have picked up my scent in the hallway, but he still paused in the doorway, surprised and confused to see me here.

His eyebrows furrowed in confusion as he watched Nina jot down some numbers on her notepad. "Nina?"

She didn't even look up. "Trinity said she didn't feel well, and I'm quite inclined to believe her, especially considering her blood pressure is extremely high. I've never seen numbers this high in a zombie or a human. I wanted you here in case she runs into problems with control. Unless something happens, please remain over there, just in case she's contagious."

Daniel's eyes focused on me. "Are you having any problems with control?"

I shook my head, which didn't help my headache. "Not that I've noticed."

He nodded and relaxed a bit, taking a seat in a chair by the door.

Moving so her body was between Daniel and me, Nina dropped the end of the stethoscope down my shirt and pressed the cold thing against my chest. She frowned and looked at her watch before moving the stethoscope to listen to my lungs.

When she put the stethoscope on the counter and scribbled on her notepad, I asked, "Well?"

"Your heart is flying as if you were running. Your lungs are clear though, and I don't hear anything else that strikes me as being odd, although I'll admit I don't do many medical checkups."

Daniel frowned slightly at that news. Considering I wasn't sure how I had contracted this illness, I hoped it wasn't airborne, or the distance between us might not be sufficient. He hadn't received the flu vaccine until later, so if it was something to do with being an original, he wouldn't notice for several weeks.

"Mind if I check your leg?" Nina asked.

Without bothering to reply, I pulled up my pant leg to reveal the faded scar.

"Thanks. It's healed cleanly. No signs of infection. I'll just peek down the back of your shirt to check your shoulder."

As she walked behind me, I let my pant leg fall back down. I held still as she pointed a flashlight down the back of my shirt collar, leaning her head uncomfortably close to mine as she peered at the scar.

"That one is fine too, so I don't think this is related to your previous injuries, unless one of them is red and inflamed?"

"No, they all look like normal scars."

Nina grabbed her notepad and sat down in a chair farther down the counter, turning her chair so she could see me. "Please start from the beginning with as many details as possible, especially timelines."

Like a well-behaved – if grouchy – patient, I complied with her request. "Just after midnight, my vision hazed for about half a second, almost like the heat haze above a highway. My instincts were unsettled, so I thought they might have detected something. When I couldn't find anything, I continued patrolling, and about an hour later it happened again.

"At that point, I realized it was actually my sight, not subterranean gases, fog, or my instincts trying to warn me about something. About that time, a tremor ran through my muscles, and they started to ache, which isn't too unusual if I do a lot of physical activity. Both the haze and tremor are happening more frequently."

Nina scribbled away on her notepad. "Does UV light bother you like normal light does?"

"I have no idea."

Nina dug around in a drawer and pulled out a flashlight. "Daniel, could you please turn off the lights? Trinity, let me know if this light bothers you."

When the lights went out, Nina turned the odd purple flashlight on and pointed it at the floor. I carefully lowered my sunglasses, but swiftly put them back on.

"It's almost as bad as normal room lighting."

"That's too bad. I was hoping to get a look at your eyes to see if they're focusing properly. Daniel, you can turn the lights back on."

Nina put the flashlight in the drawer, and as she turned around, a tremor rolled through my muscles.

"Trinity?"

I glanced over to see Daniel on the edge of his seat as he watched me intently, ready to intervene if necessary. He had seen it.

"My control is fine," I reassured him somewhat grumpily. "But nothing I do stops or affects the tremor."

Nina came over. "I saw it too. Tremors don't usually affect the entire body like that; they tend to be localized. Let me check your muscles." She lifted my arm and felt the muscles underneath. "Does the tremor itself hurt?"

"Not really. The ache in my muscles is more noticeable afterward."

She let go of my arm and stepped back to give me some space. "Is the ache getting worse?"

"Slowly."

Nina went over to a drawer and pulled out a blood collection needle and vials. With a sigh, I held out my arm.

She filled three vials and put them on the counter. "We'll have to compare your blood to the earlier samples and see if there are any differences."

I nodded and resigned myself to being down here for some time.