Evening.
The emergency building on the fifth floor of the safe-zone hospital was brightly lit.
In recent days, as the invasion of otherworldly species had grown increasingly fierce, the number of injured patients had begun to surge. Doctors and nurses hurried everywhere.
Just then, a tricycle carrying a gravely ill patient stopped at the entrance. A woman who had been looking after him sat beside him.
"Quick, someone, come quick! My husband's about to die!" the woman cried, jumping off the tricycle.
At once, doctors and nurses rushed out with a gurney and helped the patient onto it.
"What's wrong with my husband? He was fine this morning." The woman's face was stricken with panic, her heart pounding with worry.
"That's right, Doctor. I'm his older brother. He's never had any health problems," said the middle-aged man who had ridden over on the tricycle.
"We don't know yet. We'll have to examine him first," the doctor replied.
After briefly asking about the patient's condition on the way, they wheeled him into the resuscitation room, while his family was kept outside.
"The patient's in pretty bad shape. His breathing and heartbeat are irregular, and he's a little malnourished. Let's start with a blood test," a doctor said after examining him.
With the power out, the hospital's diagnostic options were limited. Aside from a few standard procedures, the doctors could only rely on their past experience.
A young nurse wiped the patient's arm with an alcohol swab, then immediately stepped forward to draw blood.
The patient's skin was sallow, and the veins stood out sharply beneath the skin of his arm. Patients like this were the easiest to draw blood from. Even a newly graduated nursing intern could manage it without trouble, unlike with children or obese patients, where finding a vein