by Max Brooks
G. Healing
Despite legends and ancient folklore, undead physiology has been proven to possess no powers of regeneration. Cells that are damaged stay damaged. Any wounds, no matter
what their size and nature, will remain for the duration of that body’s reanimation. A variety of medical treatments have been attempted to stimulate the healing process in captured ghouls. None were successful. This inability to self-repair, something that we as living beings take for granted, is a severe disadvantage to the undead. For example, every time we physically exert ourselves, we tear our muscles. With time, these muscles rebuild to a stronger state than before. A ghoul’s muscle mass will remain damaged, reducing its effectiveness every time it is used.
H. Decomposition
The average zombie “life span”—how long it is able to function before completely rotting away—is estimated at three to five years. As fantastic as this sounds—a human corpse able to ward off the natural effects of decay—its cause is rooted in basic biology. When a human body dies, its flesh is immediately set upon by billions of microscopic organisms. These organisms were always present, in the external environment and within the body itself. In life, the immune system stood as a barrier between these organisms and their target. In death, that barrier is removed. The organisms begin multiplying exponentially as they proceed to eat and, thereby, break down the corpse on a cellular level. The smell and discoloration associated with any decaying meat are the biological process of these microbes at work. When you order an “aged” steak, you are ordering a piece of meat that has begun to rot, its formerly toughened flesh softened by microorganisms breaking down its sturdy fiber. Within a short time, that steak, like a human corpse, will dissolve to nothing, leaving behind only material too hard or innutritious for any microbe, such as bone, teeth, nails, and hair. This is the normal cycle of life, nature’s way of recycling nutrients back into the food chain. To halt this process, and preserve dead tissue, it is necessary to place it in an environment unsuitable for bacteria, such as in extreme low or high temperatures, in toxic chemicals such as formaldehyde, or, in this case, to saturate it with Solanum.
Almost all the microbe species involved in normal human decomposition have repeatedly rejected flesh infected by the virus, effectively embalming the zombie. Were this not the case, combating the living dead would be as easy as avoiding them for several weeks or even days until they rotted away to bones. Research has yet to discover the exact cause of this condition. It has been determined that at least some microbe species ignore the repelling effects of Solanum—otherwise, the undead would remain perfectly preserved forever. It has also been determined that natural conditions such as moisture and temperature play an important role as well. Undead that prowl the bayous of Louisiana are unlikely to last as long as those in the cold, dry Gobi desert. Extreme situations, such as deep freezing or immersion in preservative fluid, could, hypothetically, allow an undead specimen to exist indefinitely. These techniques have been known to allow zombies to function for decades, if not centuries. (See “Recorded Attacks.”) Decomposition does not mean that a member of the walking dead will simply drop. Decay may affect various parts of the body at different times. Specimens have been found with brains intact but nearly disintegrated bodies. Others with partially rotted
brains may control some bodily functions but be completely paralyzed in others. A popular theory has recently circulated that attempts to explain the story of the ancient Egyptian mummy as one of the first examples of an embalmed zombie. The preservation techniques allowed it to function several thousand years after being entombed. Anyone with a rudimentary knowledge of ancient Egypt would find this story almost laughably untrue: The most important and complicated step in preparing a pharaoh for burial was the removal of the brain!
I. Digestion
Recent evidence has once and for all discounted the theory that human flesh is the fuel for the undead. A zombie’s digestive tract is completely dormant. The complex system that processes food, extracts nutrition, and excretes waste does not factor into a zombie’s physiology. Autopsies conducted on neutralized undead have shown that their “food” lies in its original, undigested state at all sections of the tract. This partially chewed, slowly rotting matter will continue to accumulate, as the zombie devours more victims, until it is forced through the anus, or literally bursts through the stomach or intestinal lining. While this more dramatic example of non-digestion is rare, hundreds of eyewitness reports have confirmed undead to have distended bellies. One captured and dissected specimen was found to contain 211 pounds of flesh within its system! Even rarer accounts have confirmed that zombies continue to feed long after their digestive tracts have exploded from within.
J. Respiration
The lungs of the undead continue to function in that they draw air into and expel it from the body. This function accounts for a zombie’s signature moan. What the lungs and body chemistry fail to accomplish, however, is to extract oxygen and remove carbon dioxide. Given that Solanum obviates the need for both of these functions, the entire human respiratory system is obsolete in the body of a ghoul. This explains how the living dead can “walk underwater” or survive in environments lethal to humans. Their brains, as noted earlier, are oxygen-independent.
K. Circulation
It would be inaccurate to say that zombies have no heart. It wouldnot be inaccurate, however, to say that they find no use for it. The circulatory system of the undead is little more than a network of useless tubes filled with congealed blood. The same applies to the lymphatic system as well as all other bodily fluids. Although this mutation would appear to give the undead one more advantage over humanity, it has actually proved to be a godsend. The lack of fluid mass prevents easy transmission of the virus. Were this not true, hand-to-hand combat would be nearly impossible, as the defending human would almost certainly be splattered with blood and/or other fluids.
L. Reproduction
Zombies are sterile creatures. Their sexual organs are necrotic and impotent. Attempts have been made to fertilize zombie eggs with human sperm and vice versa. None has been successful. The undead have also shown no signs of sexual desire, either for their own species or for the living. Until research can prove otherwise, humanity’s greatest fear—the dead reproducing the dead—is a comforting impossibility.
M. Strength
Ghouls possess the same brute force as the living. What power can be exerted depends greatly on the individual zombie. What muscle mass a person has in life would be all he possesses in death. Unlike a living body, adrenal glands have not been known to function in the dead, denying zombies the temporary burst of power we humans enjoy. The one solid advantage the living dead do possess is amazing stamina. Imagine working out, or any other act of physical exertion. Chances are that pain and exhaustion will dictate your limits. These factors do not apply to the dead. They will continue an act, with the same dynamic energy, until the muscles supporting it literally disintegrate. While this makes for progressively weaker ghouls, it allows for an all-powerful first attack. Many barricades that would have exhausted three or even four physically fit humans have fallen to a single determined zombie.
N. Speed
The “walking” dead tend to move at a slouch or limp. Even without injuries or advanced decomposition, their lack of coordination makes for an unsteady stride. Speed is mainly determined by leg length. Taller ghouls have longer strides than their shorter counterparts. Zombies appear to be incapable of running. The fastest have been observed to move at a rate of barely one step per 1.5 seconds. Again, as with strength, the dead’s advantage over the living is their tirelessness. Humans who believe they have outrun their undead pursuers might do well to remember the story of the tortoise and the hare, adding, of course, that in this instance the hare stands a good chance of being eaten alive.
O. Agility
The average living human possesses a dexterity level 90 percent greater than the strongest ghoul. Some of this com
es from the general stiffness of necrotic muscle tissue (hence their awkward stride). The rest is due to their primitive brain functions. Zombies have little hand-eye coordination, one of their greatest weaknesses. No one has ever observed a zombie jumping, either from one spot to another or simply up and down. Balancing on a narrow surface is similarly beyond their ability. Swimming is also a skill reserved for the living. The theory has been put forth that, if an undead corpse were to be bloated enough to rise to the surface, it could present a floating hazard. This is rare, however, as the slow rate of decomposition would not allow by-product gas to accumulate. Zombies who walk or fall into bodies of water will more likely find themselves wandering aimlessly across the bottom until eventually dissolving. They can
be successful climbers, but only in certain circumstances. If zombies perceive prey above them, for example, in the second story of a house, they will always attempt to climb to it. Zombies will try to scale any surface no matter how unfeasable or even impossible. In all but the easiest situations, these attempts have met with failure. Even in the case of ladders, when simple hand-over-hand coordination is required, only one in four zombies will succeed.
2. Behavioral Patterns
A. Intelligence
It has been proven, time and again, that our greatest advantage over the undead is our ability to think. The mental capacity of the average zombie ranks somewhere beneath that of an insect. On no occasion have they shown any ability to reason or employ logic. Attempting to accomplish a task, failing, then by trial and error discovering a new solution, is a skill shared by many members of the animal kingdom but lost on the walking dead. Zombies have repeatedly failed laboratory intelligence tests set at the level of rodents. One field case showed a human standing at one end of a collapsed bridge with several dozen zombies on the other side. One by one, the walking dead tumbled over the edge in a futile attempt to reach him. At no time did any of them realize what was happening and change their tactics in any way. Contrary to myth and speculation, zombies have never been observed using tools of any kind. Even picking up a rock to use as a weapon is beyond their grasp. This simple task would prove the basic thought process involved in realizing that the rock is a more efficient weapon than the naked hand. Ironically, the age of artificial intelligence has enabled us to identify more easily with the mind of the zombie than that of our more “primitive” ancestors. With rare exceptions, even the most advanced computers do not have the ability to think on their own. They do what they are programmed to do, nothing more. Imagine a computer programmed to execute one function. This function cannot be paused, modified, or erased. No new data can be stored. No new commands can be installed. This computer will perform that one function, over and over, until its power source eventually shuts down. This is the zombie brain. An instinct-driven, unitask machine that is impervious to tampering and can only be destroyed.
B. Emotions
Feelings of any kind are not known to the walking dead. Every form of psychological warfare, from attempts at enraging the undead to provoking pity have all met with disaster. Joy, sadness, confidence, anxiety, love, hatred, fear—all of these feelings and thousands more that make up the human “heart” are as useless to the living dead as the organ of the same name. Who knows if this is humanity’s greatest weakness or strength? The debate continues, and probably will forever.
C. Memories
A modern conceit is that a zombie retains the knowledge of its former life. We hear stories of the dead returning to their places of residence or work, operating familiar machinery, or even showing acts of mercy to loved ones. In truth, not a shred of proof exists to support this wishful thinking. Zombies could not possibly retain memories of their former lives in either the conscious or subconscious mind, because neither exist! A ghoul will not be distracted by the family pet, living relatives, familiar surroundings, etc. No matter who a person was in his former life, that person is gone, replaced by a mindless automaton with no instinct other than for feeding. This begs the question: Why do zombies prefer urban areas to the countryside? First, the undead do not prefer cities, but simply remain where they are reanimated. Second, the main reason zombies tend to stay in cities instead of fanning out into the countryside is because an urban zone holds the highest concentration of prey.
D. Physical Needs
Other than hunger (discussed later), the dead have shown none of the physical wants or needs expressed in mortal life. Zombies have never been observed to sleep or rest under any circumstances. They have not reacted to extreme heat or cold. In harsh weather, they have never sought shelter. Even something as simple as thirst is unknown to the living dead. Defying all laws of science, Solanum has created what could be described as a completely self-sufficient organism.
E. Communication
Zombies have no language skills. Although their vocal cords are capable of speech, their brain is not. The only vocal ability appears to be a deep-throated moan. This moan is released when zombies identify prey. The sound will remain low and steady until physical contact is made. It will then shift in tone and volume as the zombie commences its attack. This eerie sound, so typically associated with the walking dead, serves as a rallying cry for other zombies and, as has been recently discovered, is a potent psychological weapon. (See “On the Defense.”)
F. Social Dynamics
Theories have always proliferated that the undead function as a collective force, from an army controlled by Satan to an insect-like pheromone-driven hive to the most recent notion that they achieve group consensus by telepathy. The truth is that zombies have no social organization to speak of. There is no hierarchy, no chain of command, no drive toward any type of collectivization. A horde of the undead, regardless of size, regardless of appearance, is simply a mass of individuals. If several hundred ghouls converge on a victim’s location, it is because each one is drawn by its own instinct. Zombies appear to be unaware of one another. Individuals have never been observed to react to the sight of one another at any range. This goes back to the question of sense: How does a zombie distinguish between one of its own and a human or other prey at the same range? The
answer has yet to be found. Zombies do avoid one another in the same way they avoid inanimate objects. When they bump into one another, they make no attempt to connect or communicate. Zombies feasting on the same corpse will tug repeatedly on the meat in question rather than shove a competitor out of the way. The only suggestion of communal effort is seen in notorious swarm attacks: the moan of a ghoul calling others within earshot. Once they hear the wail, other walking dead will almost always converge on its source. An early study theorized that this was a deliberate act, that a scout used its moan to signal the others to attack. However, we now know that it happens purely by accident. The ghoul that moans at the detection of prey does so as an instinctive reaction, not as an alert.
G. Hunting
Zombies are migratory organisms, with no regard for territory or concept ofhome. They will travel miles and perhaps, given time, cross continents in their search for food. Their hunting pattern is random. Ghouls will feed at night and during the day. They will stumble through an area rather than deliberately searching it. Certain zones or structures will not be singled out as more likely to contain prey. For example, some have been known to search farmhouses and other rural structures while others in the same group have moved by without even a glance. Urban zones take more time to explore, which is why the undead remain longer in these areas, but no building will take precedence over another. Zombies appear to be totally unaware of their surroundings. They do not, for example, move their eyes in a way that would take in the information of a new setting. Shuffling silently, with a thousand-yard stare, they will wander aimlessly, regardless of location, until prey is detected. As discussed earlier, the undead possess an uncanny ability to home in on a victim’s precise location. Once contact is made, the previously silent, oblivious automaton transforms into something more closely related to a guided missile. The
head turns immediately in the direction of its victim. The jaw drops, lips retract, and, from the depths of its diaphragm, comes the moan. Once contact is made, zombies cannot be distracted by any means. They will continue to pursue their prey, stopping only if they lose contact, make a successful kill, or are destroyed.
H. Motivation
Why do the undead prey upon the living? If it has been proven that human flesh serves no nutritional purpose, why does their instinct drive them to murder? The truth eludes us. Modern science, combined with historical data, has shown that living humans are not the only delights on the undead menu. Rescue teams entering an infested area have consistently reported them stripped of all life. Any creatures, no matter what their size or species, will be consumed by an attacking zombie. Human flesh, however, will always be preferable to other life forms. One experiment presented a captured specimen with two identical cubes of meat: one human, one animal. The zombie repeatedly chose the human. Reasons for this are still unknown. What can be confirmed, beyond any shadow of doubt, is that instinct brought on by Solanum drives the undead to kill and devour any living creature they discover. There appear to be no exceptions.
I. Killing the Dead
While destroying a zombie may be simple, it is far from easy. As we have seen, zombies require none of the physiological functions that humans need to survive. Destruction or severe damage of the circulatory, digestive, or respiratory system would do nothing to a member of the walking dead, as these functions no longer support the brain. Simply put, there are thousands of ways to kill a human—and only one to kill a zombie. The brain must be obliterated, by any means possible.
