Byrne looked toward the forest, where presumably the entire town had been dragged. He wasn’t sure he wanted to know what was out there.
They agreed to perform a cursory search of the town in hopes of finding any clues before heading blindly into the wilderness. Every house was in the same condition. These people had never known what hit them. The attack had come through the broken windows and doors while they were sleeping and their bodies had been removed through the same egresses. There were no bullet holes or spent casings, no discolorations on the walls or ceilings to suggest aerial dispersion, or any other indication of the means by which these people had been overcome. All that remained of them were smears and patterns of blood to mark where they’d fallen and the direction of their posthumous passage.
Whatever livestock they’d held was gone as well. The stables and pens were vacant, the straw desiccated and dusty. There were no fresh tracks or any other sign animals had even been housed there recently, with the exception of sporadic mounds of fecal material, which Byrne theorized belonged to animals other than those once contained in the pens.
The spoor was black and runny, a trait caused by a high concentration of blood. The fact the same feces was scattered throughout the town suggested it came from one species, and not one that had been domesticated or housed in the pens or pastures. Richards suggested it belonged to a species of scavenger that had fed upon the victims while they were either incapacitated or dead, which made a certain amount of sense. Byrne was no expert on feces, nor did he have any desire to be, but he couldn’t dismiss the observation that much of the spoor appeared to be older than forty-eight hours, especially that found near the fringes of town by the majority of the empty livestock pens.
The establishments in what passed for the commercial district were different. There was nothing peaceful about the way the patrons of the ramshackle bars and restaurants had gone. The walls and ceilings were spattered with blood. Tables lay overturned amid shattered bottles and plates. Dried blood flaked from the wooden floor like lichen and formed a brick-red path onto the dirt road where the victims had either crawled or been dragged out into the street. The dirt remained disturbed where many had fallen and struggled to drag themselves in the opposite direction from which their remains were ultimately taken.
Byrne performed the ELISA assay on another half-dozen blood samples he’d collected from various points around town while the others explored the military barracks. It appeared as though the majority of the forces had been dispatched before the siege. Bunks remained perfectly made and footlockers were half-empty. There were no boots or fatigues to be found in most of the buildings, which reminded Byrne more of mobile homes stuffed full of cots than actual quarters. The inner walls of the guard shack were riddled with bullet holes and covered with blood, as was the westernmost barracks, inside of which it looked much like all of the other dwellings.
Graves was able to determine that the forces had been dispatched three weeks ago to Koindu, a town forty miles to the northeast on a finger of land thrust straight into Guinea on one side and Liberia on the other, presumably as a deterrent to the advances of Boko Haram. Richards speculated the jihadists must have gained knowledge of the maneuver and swept southwest along the banks of the Moa River, which flowed directly behind the outpost.
The assays had provided no new information, but had confirmed the presence of IgG and IgH antibodies in comparable amounts. It was only while waiting for the others to complete their search of the barracks that Byrne decided to isolate the blood from the spoor near the front gates, where Anthony remained as his personal guard, and run it through a separate ELISA assay. The results solidified a theory that had yet to fully form in his mind.
“Interesting,” Byrne whispered.
“What?” Anthony said. He peeked back over his shoulder before returning his attention to the gate blocking the lone road into the outpost.
“This blood sample. From the stool. It has elevated levels of eosinophils and acetylcholine receptor antibodies.”
“So what?”
“Acetylcholine receptors purvey chemical signals from the nerves to the muscles. Eosinophils are the white blood cells responsible for combating allergic responses, especially in relation to the respiratory system.”
“What are you getting at?”
“The nervous system in the first thing affected by envenomation, followed in short measure by the respiratory system. Think of a cobra. After it bites its prey, its venom goes straight into the bloodstream and to the nerves, where it blocks the signals from the brain to the muscles, causing paralysis. Immune responses work much more slowly. The body produces increased amounts of white blood cells in response to the elevated levels of histamine caused by the venom. Eosinophils, specifically, help combat inflammation of the lungs, which is the ultimate denouement of a snakebite. First the prey can’t move, then it can’t breathe. That might be an oversimplification, but you get the gist.”
“We already knew we were dealing with a type of venom. That doesn’t change anything.”
“But it tells us a lot about the animals that produced the spoor.”
“Great.”
“Don’t you see? They’re ophiophagic. The elevated levels of eosinophils and acetylcholine receptor antibodies aren’t present in the blood of the victims, but they’re in high concentration after passing through the bodies of the scavengers. They’re not sensitive to the venom because they already have the antibodies to combat it. Like a mongoose or an opossum—”
“A honey badger.”
“Exactly.”
“But none of those are large enough to prey upon people, no matter how incapacitated they are.”
Byrne stood and paced the front deck of the empty barracks. Richards and Warren emerged from behind a stand of trees on the far side of the field, while Graves appeared from the direction of the river.
Anthony was right. He couldn’t think of a single ophiophagic species that preyed upon man, nor could he think of one that scavenged. Ophiophagy was a specific adaptation that evolved based on the prevalence of venomous sources of food. So what did that imply?
“We’ve stalled long enough,” Richards said.
Byrne understood what he meant. The time had come to follow the trail into the jungle, where any number of potential dangers could be lurking behind any tree trunk or waiting in the trees with weapons trained down on them. They’d be sacrificing every advantage the open space afforded.
“Tell me you learned something we can use,” Warren said. He nodded toward Byrne’s case.
Byrne shook his head and glanced at Anthony. He was reluctant to share what he’d found until he was able to make sense of the results. They didn’t make sense, at least not in this context. Either the species responsible for the spoor was a scavenger that had seemingly overnight evolved the ability to manufacture antibodies in the levels required for the ingestion of high quantities of venom, or the production of antibodies was the adaptation of a predatory species that had somehow developed the ability to produce venom.
The rain fell in rivulets through the canopy, hitting the muddy ground with a sound like a rushing river. Byrne skirted the sucking puddles and battled through the wet shrubs. Guinea fowl called from the brush and scampered away when they neared. Macaws squawked and swifts darted through the treetops. Byrne watched for the monkeys he’d heard on Dr Odongo’s recording, but didn’t see a single species that didn’t have wings or scales.
The trail they’d been following since leaving Daru was still evident, although by now it had become a narrow stream, obscuring whatever footprints might have survived the parade of bodies being dragged over them.