"Something's wrong. Definitely wrong. Stop for now. These zombies are acting like they've got target-tracking radar. The moment we see them, they charge straight at us…"
"If this keeps up, either I'll collapse from exhaustion, or you'll run out of bullets."
Twenty minutes later, Lux stopped and called MDR back.
In just those twenty minutes—less than two kilometers—he had already killed twenty-three zombies.
On average, more than one per minute.
This time, it was completely different from before. The zombies' target-seeking range had almost instantly expanded several times over.
Lux was absolutely unwilling to believe that every zombie in this area had suddenly evolved within a single day.
That meant the problem had to be on their side.
Just as he was about to turn back and find a safe corner to calmly think through what was going wrong, Lux's gaze suddenly stopped on Bob's bandaged forehead.
"…Could it be blood?"
Recalling the first time he killed a zombie that morning—when his grip had split open from the backlash, and the second zombie's movement speed suddenly increased drastically, as if it had entered a berserk state—Lux frowned.
That seemed to indicate that zombies also had an extremely sharp sense of smell.
If his guess was correct, then this was bad.
Bob, with a wound on his forehead, was basically a beacon even worse than noise.
Noise merely prompted zombies to hunt.
But the smell of blood… that was practically announcing that there was a feast over here.
The priority of blood scent was definitely far higher than the noise produced by a phone.
Fortunately, he had discovered this early. Otherwise, if they had entered the zombie-dense city center, they would probably have been surrounded instantly.
"HK, MDR—do either of you have perfume?"
Even though he couldn't confirm his hypothesis, there was no way to test it right now. All he could do was try to mask Bob's scent first.
"I'm very sorry, Lux. I don't carry something that useless. But… do you have a scent you like? If we find some later, I could consider spraying it."
HK416 asked curiously.
"No. I suspect it's because Old Bob has the smell of blood on his head, so the zombies can detect us from far away."
"Oh! That's very likely. MDR thought her recon module was malfunctioning. Turns out it's this unlucky uncle's fault. But sorry, I don't have perfume either."
MDR shrugged.
"Let's find a safe building to hide in first. Then HK, change his bandages and see if the wound has scabbed over."
"If we don't figure out why the zombies' detection ability suddenly increased and just head into a densely populated district, we'll get swarmed. That would be troublesome."
After thinking for a moment, Lux spoke.
"There's a shop thirty meters away. We can go there."
MDR pointed into the distance.
"Alright, let's go there."
Lux took the lead.
When they were ten meters from the shop, Lux's enhanced hearing—strengthened by the gene serum—picked up furious, hungry roars from inside.
Then he saw a female zombie in a dress, limping toward him with a twisted ankle.
Her face was still pretty and uninjured, but the bloodshot pupils betrayed her identity.
"…Old Bob, you take this one."
Lux handed the katana to Bob.
If the situation at X High School turned bad, he would abandon Bob and leave with MDR and HK416.
Before that, at least he could help him overcome his fear of zombies a little.
From the blood-stained baton at Bob's waist, Lux could guess he had probably killed a zombie before.
But one was far from enough.
And this zombie wasn't fast. With his current reaction speed and strength, Lux could deal with it even using just the scabbard.
"Okay…"
Bob trembled as he gripped the katana's hilt, his body stiff as he took a stance.
"Don't use too much force. Just destroy her brain. Slashing or stabbing both work."
Lux reminded him calmly. Killing zombies was something you got better at with practice.
After killing more than twenty zombies earlier, he had figured out that stabbing consumed the least stamina—but since zombies moved, it required skill to avoid missing.
Missing a stab meant danger, since slashes needed space to wind up, and missing allowed the zombie to close in.
Slashes and horizontal cuts consumed more stamina but were less likely to miss.
"S-sorry! Please rest in peace, miss!"
Bob shouted to boost his courage, then wildly swung the katana at the female zombie.
The fierce strike buried itself deep into her shoulder blade and got stuck.
The female zombie let out an enraged roar and lunged at Bob with arms wide open.
Lux struck her abdomen with the scabbard, sending her flying two meters back. Bob was dragged forward a step before wrenching the katana free.
"Aim for the head. Calm down. We won't let you die."
Lux said flatly.
Bob nodded. As the zombie struggled to crawl up, he brought the katana down and split her skull open.
"Sorry for causing you trouble."
Bob awkwardly handed the katana back.
"Get inside. I'll gather supplies. MDR, stand guard outside and alert me if zombies come. HK, change Old Bob's bandages and check if the bleeding has stopped."
"Don't I need to clear the inside for zombies?"
MDR asked, puzzled.
"No need. If there were any, the noise would've drawn them out already. And I didn't hear any movement inside."
"What we should worry about is whether the blood smell will attract more zombies in this area."
With that, Lux quickly entered the shop and stuffed high-calorie solid snacks like chocolate from the shelves into his backpack.
HK416 efficiently and professionally removed the bandages from Bob's head.