Flood (Halo)
The Flood is a fictional alien life form in the video games Halo: Combat Evolved and Halo 2.
Overview
The Flood is a parasitic virulent life form which is spread by infected carrier hosts. The Flood appears in three primary forms: Infection, Combat and Carrier forms, but also have more mysterious forms like the Brain form and the Juggernaut form. All of these have an attraction to any sentient lifeform and will try to attack/infect any they encounter. The lifecycle of the Flood begins at Infection form as a small, frail, gas-bloated creature that leaps upon a host and attempts to drive in three barbed tentacles (although the small spores that some Flood are seen to release are also used to infect, as 343 Guilty Spark explains over the din of The Library level in the first game). From here, the host is paralysed and loses consciousness. The infection form gores itself deep into its host, usually in the chest. For a while it plays with its new body, and over time it mutates it by changing hormones and replacing the host's nervous system with its own tentacles. The host is never fed, and is carelessly treated. Often limbs become infected and begin to rot. Vital organs are liquified and the neck is broken. The disused head of the victim eventually falls off. If the host is of suitable size eg. Human or Elite, long whip like tentacles emerge from the arms as weapons. If not of suitable size, then the next stage of mutation occurs early. The body becomes so bloated and rotten that it may no longer be used as a Combat form. Smaller Infection forms grow within the ball of flesh, as it swells with gas and juice. Eventually the Carrier form falls over (or simply gives up) and explodes. Roughly 4-9 infection forms are emitted and continue the cycle.
There is speculation into many other forms such as spores, unknown and shapeless flesh lumps which appear in Halo 2, brain forms that strip information, Gravemind and even the Juggernaut form (which has never appeared in any Halo game as of this time).
One ability of the Flood mentioned by 343 Guilty Spark that is the Flood actually terraform the atmosphere to suit them: "Your environment suit should serve you well when the Flood begins to alter the atmosphere. You are a good planner." This hints that the Flood live in an environment noxious to most other living creatures. It might be surmised that the Flood can live in almost any biosphere, and the Flood run around in any environment without any protection.
The origin of the Flood remains unknown, lost in the immense amount of time since those events took place. What is known is that the Forerunners constructed research facilities situated over gas giants and later huge "Fortress World" installations (called "Halos" by the Covenant) to contain and study the Flood. In the event that the Flood was released, which it was, the Halos were designed to destroy all sentient life in the galaxy. The thinking behind this is that if the Flood has no food then it will eventually starve to death, allowing the galaxy to slowly re-populate and preventing the Flood from spreading to even more galaxies throughout the Universe. In the sequel, Halo 2, some levels took place onboard a Forerunner facility. Throughout the levels were many small, decorative pedestals supporting objects that are similar in shape and colour to various forms of Flood. These decorations are repeated many times, too precisely to have been created by the Flood, and are probably intentional references to it.
Flood forms
Infection forms
The infection forms are small, tentacled creatures which have their own defined biological framework, and therefore are not dependent upon a host. Individually they are weak and fragile; they appear to come in swarms. An infection form will seek out any sentient life of capable bio-mass and calcium deposits to sustain itself, and proceed to attempt to use the creature as a host, by tapping into the spinal system, suppressing the host's consciousness, embedding itself in the thoracic cavity, and releasing spores which cause the host to mutate. (343 Guilty Spark mentions these "spores" during his own synopsis of the Flood life-cycle, which may be either another term for the Infection form, or an even more basic form of the Flood.) At this point, the infected creature mutates into a possible one of four other forms. The infection form parasites attack in a flood-like swarm (hence the Flood moniker) that rapidly advances on host organisms, then physically attach themselves to a host as they try to burrow into its chest. Once inside the organism will begin to modify the host's genetic code and take over. The infection form cannot attach to a host if the host is protected by a personal energy shield; contact with the shield will make them explode with a distinct "pop" sound and will have a minimal effect on the shield's strength. However, if several dozen try to attack a shielded host they will gradually deplete their shields to the point that they are vulnerable. Thus, soldiers such as the human SPARTAN soldiers and the Covenant Elite and Hunters, except Jackals, are able to at least have some protection against the Flood and mount a counter attack, but unshielded troops (the majority of both armies) such as UNSC Marines and Covenant Grunts, Drones, and Brutes are quickly and easily obliterated by an attack by masses of infection forms. The shape and method of infection of these forms bear striking resemblences to the facehuggers from the Alien film saga.
Combat forms
If the host is strong or deemed "useful" by the parasitic infection form, then the host will be converted into a warrior or worker form, used in defensive/offensive situations as well as maintaining and repairing machinery. In Halo 2, the Flood have the ability to pilot and repair vehicles, which suggests that the Flood utilize the memories and knowledge of their hosts. The Halo novels also make reference to the Flood leaching the memories of their hosts to use equipment. These warrior or combat forms are extremely strong and agile and can jump an extremely long distance and extremely high, with the Covenant Elite-derived combat forms sometimes being able to use the energy shielding technology on their remaining Elite armour in Halo 2. These forms can use all UNSC and Covenant weaponry, but are not seen using the Fuel Rod Gun (and in Halo they did not use sniper rifles). Combat Flood are also capable of unarmed combat, striking with whip-like tentacles protruding from the arms of the host. These tentacles can grow out of the arm at an alarming rate and simply break the nearby bones and shove them out of the way. Flood are also known to play dead after being killed by non-explosive weapons (excluding point-blank shotgun blasts and the energy sword), usually if the head or brain of their host is severed/damaged, eliminating what is left of the host's central nervous system. The only sure way to know a Flood-mutated organism is dead is by shooting the infection form residing within their chest area or shred the body with a shotgun blast, explosives or an energy sword. It must be noted however, that surrounding infection forms have been known to enter the downed combat form and 'bring it back to life'. It is advisable in an area where infection forms are in the vicinity to completely destroy the combat form's body. They also carry the grenades equipped before the host was infected, which are dropped when shot. As the Flood care only about food, they totally ignore any threat to themselves and will often kill themselves and other Flood to kill an opponent.
UNSC Marines and Covenant Elites are typically converted into combat forms. To tell the difference, the Covenant type are larger and faster with stiff tentacles that are used to slash, with their heads hanging limply over their backs as though their neck bones have been removed, and drop Plasma Grenades when shot. In one encounter the Elite combat forms have active camoflague although it is unknown if they are capable of operating it or were just wearing it when they were infected. By Halo 2, the Elite forms have learned to use their remaining armour's energy shields and some can be seen sporting them. The Human type is smaller and slower and a lot more frail in their appearance, and drop Fragmentation Grenades. However, the human combat forms are actually a lot stronger in terms of melee attacking, with whip-like tentacles. Both forms carry assorted weaponry, showing no discernible preference for weapon type or origin.
When battling Flood combat forms, the best possible weapons of choice are the shotgun or energy sword. Failing that, weapons capable of headshot kills such as the carbine or battle rifle or assault rifle (excluding the sniper and beam rifle, which are totally ineffective as their heavy, high-velocity rounds pass right through the form without causing any major damage) or weapons with high rate of fire like SMGs or Plasma Rifle are extremely useful. Removing the combat form's head is of no consequence; the combat form doesn't need it. However, it is possible to remove the infection form within with a single shot placed at the region where the heart would be, or in the case of the Flood, where the tentacles of the infection form are visible. Without the infection form inside, the host simply drops to the ground harmless; at least until another infection form reanimates it. Killing human forms in this manner is more difficult than elites due to the ballistic body armor left over the human host's chest; the best option left after that is to destroy their arms, as without them they are incapable of attacking.
Carrier forms
The second possible form an infected host can take is that of the carrier, which presumably only happens to creatures that are physically or mentally unsuitable to be combat forms. Carriers grow large sacs which contain several infection forms. When a carrier is in close proximity to any number of suitable hosts, it triggers some manner of biochemical reaction, causing the sacs to explode and spread the infection forms in order to infect more hosts. This continues the Flood life cycle. Also, as the Flood do not care for their physical forms, older and worn combat forms can be turned into carriers once they have outlived their usefulness. A notable problem with the carrier forms is that the explosion of their bodies can set off nearby explosives, but a skilled player can shoot them at the right moment to set off a series of detonations which can kill the infection forms released as well as other opponents. In addition, the explosions from the carrier forms themselves act as grenades, often causing a powerful enough force to send other nearby combat and carrier forms flying (possibly killing them). Firing directly at carriers in a group of Flood can cause chain reaction explosions with other carriers, thus helping to eliminate potential threats and destroying many, if not all, of the infection forms released.
Covenant Grunts, Jackals, and decayed combat forms are often used to serve as carrier forms.
Juggernaut
The Flood Juggernaut is one of the most enigmatic of the Flood forms. They were initially planned to be encountered in Halo 2, but it was rejected by Bungie. Modders who placed the Juggernaut where it was originally intended to go (a pair at the start of the High Charity level, possibly explaining why a rocket launcher can be found beside the Pelican dropship wreck) found that it is extremely difficult to kill them, since one hit by the Juggernaut's powerful, whip-like arms will kill the player. It is also capable of taking a lot of damage and surviving. Similar in jumping ability to the combat forms, and similar in walking speed and style to the carrier (although capable of sprinting as fast as a combat form), the Juggernaut is a powerful foe which will become more aggressive when its partner is killed, in an uncannily similar fashion to Covenant Hunters. The Juggernaut was not completed and so has no death animations, meaning it simply becomes still when killed, but otherwise is a functioning enemy. The Juggernaut seems likely to be some form of boss or strong enemy (such as a Hunter), although its purpose is never revealed. It is physically taller than a Hunter and has a physical form resembling that of a carrier, but with tall, skeletal legs and unusually long arms which are essentially just extended tentacles. These arms bear large claws - identical to a Hunter. Many people seem to think that the Juggernaut is an infected Covenant Engineer, due to the body shape and tentacles. However, Engineers float, and not walk, not to mention Engineers are a lot smaller in size. Although unlikely due to the Hunter's biological configuration, this bears the most similarity to the Juggernaut out of all of the Covenant species, most notably the legs, claws, body shape, brute strength and surprisingly swift movement as displayed by a charging Hunter. However, this cannot be the case, seeing as how the Hunters are actually swarms of wormlike creatures operating under a single consciousness, and thus cannot be infected, which may have been why it was rejected. The Juggernaut was previously unknown to the Halo community until the code and models for the creature were found buried in the Halo 2 disc's coding. Plans for the Juggernaut's encounter with the Arbiter can be found on a drawn top-down view of a Quarantine Zone map blue-print on page 142 of the Halo Art Book, and on one of the art pieces on the Halo 2 LE DVD. The drawing depicts an area actually seen ingame (it is the location on Quarantine Zone right after the battle inside the structure and the descent down the shaft) describing when and where Juggernauts would appear, and describes "this is the last time we see the Sentinels winning" and "Once the Juggernauts show up, the Sentinels start to get their asses kicked." One can just imagine a Juggernaut reaching up on its long stilt-like legs, and snatching a Sentinel Enforcer out of the sky with its long tentacles and tearing it apart.
A video of the Flood Juggernaut in action can be seen here.[1] [2]
Brain forms
Brain forms are large, spongy Flood forms which resemble a large bag of flesh with tentacles. They are used to collect information on important things, such as codes, planet locations and information about the species that the Flood can infect. In Halo, Captain Jacob Keyes was subjected to an 'interrogation' of sorts by one of these forms before finally being assimilated by the Flood form. The form containing Keyes also had other limbs protruding from its 'body' - these are likely those of a high-ranking Covenant officer, possibly a Ship Master, also being used as a source of information.
Over time the Brain form strips memories and information from its victims, but is not able to take memories that the victim is trying to hide from it (in Keyes's case, the location of Earth). Many other individuals are also absorbed into the brain form, but are simply used as food sources. All body tissues and bones are soon reduced to fluid, and is digested as the brain slowly absorbs the information. Eventually the brain form is used to create more infection forms.
Command forms
The command forms, due to their limited exposure in the Halo trilogy, are not well understood. Their purpose is not exactly known. The Gravemind from Halo 2 is also believed to be a command form over the Flood on Installation 05 (Delta Halo).
Flood details
Late in Halo 2 it is revealed by 343 Guilty Spark that there were originally seven Halos; six currently remain after one (Installation 04) was destroyed in the first game. As it is believed that each Halo has a firing range of 25,000 light years, there are still enough Halos to destroy most sentient life in the galaxy, but not all.
The Flood on Installation 04 were completely destroyed in Halo: Combat Evolved and in Halo 2 they returned with the ability to operate in-game vehicles. The Flood is apparently led by Gravemind, a massive creature that dwells beneath Delta Halo's Library and on High Charity, although the player gains more of a sense that the Gravemind "corrals" the flood rather than leading it in the traditional sense. Captain Jacob Keyes is absorbed into a Brain form, which occupies the Truth and Reconciliation, a Covenant Cruiser in Halo: Combat Evolved. It is not currently known if there is a Gravemind in each Halo, or if the Gravemind encountered on Delta Halo is the controller of all Flood. The Gravemind is also thought to be the collection of the Flood's minds, not the leader of the Flood.
"The Flood" were probably named as such due to their overwhelming numbers. However, it may also be a reference to the Great Flood which wiped out the sinful in the Biblical story of Noah's Ark. This is supported by the existence of an enormous, enigmatic Forerunner structure believed to be located under the ruins of Mombassa's outskirts known as "The Ark" which can remotely control the Halos; the only thing that saved Noah from the Flood.