Tilmuhl had many tricks up its sleeve. 

Some announced themselves with fever and vomiting. Others waited in water, mud, blood, or the mouthparts of insects. Some entered quietly and remained until a person’s organs began failing in sequence. The jungle did not hate them. Hatred implied attention. It simply possessed more methods of living than their bodies had methods of refusing.

The VSEA fought back with refrigerators, needles, boiled instruments, inspection schedules, sealed water, treated insect nets, medical ledgers, and a discipline that seemed excessive until the first man began shivering in heat.

Mehrab placed a cotton ball against the final injection site.

“Hold zhat.”

The recruit did.

“You may feel feverish tonight. Your arms will hurt. Do not drink alcohol. Drink water. Eat even if you don’t feel hungry.”

“I’m supposed to report to Second Lieutenant Obs’rt.”

“You are.”

“Today?”

Mehrab looked at him.

“Yes. The injections have not killed you yet.”

The man lowered the cotton.

“Is he difficult?”

“Obs’rt?”

“Yes.”

Mehrab decided to change his answer after dwelling on something for a moment.

“No.”

The recruit waited.

Mehrab capped the vial.

“He is exact.”

The man seemed to find this less reassuring than difficult.

Mehrab signed the bottom of the form, tore away the recruit’s copy, and handed it to him.

“Administration block. End room. Knock before entering and give him zhat.”

The human took the paper.

“Anything else?”

“Wear your netting. Don’t drink from a pipe unless you know where it begins. Don’t walk barefoot. Don’t pet anyzhing because it appears friendly. If you develop a fever, come here before you decide it's nozhing.”

The recruit nodded.

“And don’t nod merely because you want me to stop speaking.”

The recruit stopped. Mehrab opened the door. The young man left for the administration block carrying his medical form and several microscopic previews of the country now circulating through his blood.

Mehrab watched him go.

Clean boots, straight back, one sleeve still rolled up. By the end of the month the boots would be gray-brown and the uniform bleached at the shoulders. The man would either become careful or become ill. Sometimes both.

Mehrab closed the door and turned toward the examining room's sink, washing then drying his hands. 

Another patient waited outside.

This one was a yinglet he did not know.

He sat hunched on the bench with both arms wrapped across his abdomen, wearing a boilersuit that was unbuttoned, frayed, and worn. His fur had once been pale brown but now appeared patchy. Angry red lesions had spread along the neck, chest, and the edges of his ears. In several places he had scratched through the skin. A sour animal odor clung to him beneath the smell of cheap soap.

Mehrab opened the door again.

“You.”

The stranger looked up.

“Inside.”

He entered with the cramped movements of someone attempting not to let his own skin touch itself.

Mehrab shut the door.

“Name?”

The yinglet told him.

“From where?”

A settlement north of Lenkerk. Not VSEA. Freight laborer. He had come to the base because the town physician had gone upriver two weeks earlier and had not returned.

Mehrab put on gloves.

“How long?”

“Four days.”

“Why did you wait?”

“Zhought it would stop.”

“Did it?”

The stranger looked down.

“No.”

Mehrab examined the lesions. Jungle-mange. Probably the common variety, though common did not mean harmless. A parasite, fungus, or both, Tilmuhlan medical arguments continued over classification because the infection behaved differently depending on host species and season. It took readily to yinglet fur, established itself beneath the upper layers of skin, and drove its victims into such relentless itching that secondary infections often became the greater danger.

Back in the Heart, yinglet immunity had the reputation of being unassailable. It attacked most intruders quickly and decisively. Generations of better nutrition, clean water, vaccines, and medical care had made that reputation seem almost universal.

Tilmuhl did not recognize it.

The organisms here had developed in conversation with other bodies, other climates, other failures. The yinglet immune system arrived full of old victories and found no one obliged to fight according to familiar rules.

Mehrab took off the yinglet's boilersuit and pushed it aside with his foot, then continued examining. He parted the fur along the stranger’s shoulder and inspected the skin beneath, finding more lesions and severe irritation.