The Infection, sometimes referred to as the ancient sickness, bright light, or the plague, is the main antagonistic force in Hollow Knight, leading to the deaths of thousands of bugs and ultimately the downfall of the kingdom of Hallownest.
Description & Effects
While much of the game uses softer blue and black tones, the Infection often manifests in a bright orange. This orange tone is most commonly seen in the colour of an infected bug's eyes, though it can also be seen in spores and even projectiles. Infected bugs release splatters of orange fluid when struck, while non-infected bugs release white particles of SOUL.
Other more noticeable physical mutations that can be caused by the Infection include:
Large orange cysts
Clouds of orange gas hovering around the victim
The Infection, however, has shown to have a much bigger effect on the behaviour of bugs, with different degrees of severity. In the case of dead bugs such as Husks, their bodies are reanimated with only a small fragment of their mind remaining. It is a different case with living bugs, as they may be sent into a sort of waking coma as can be seen with Sly and Bretta. The best example is Myla, as, throughout the Knight's journey, Myla slowly loses her mind and succumbs to the Infection.
Other behavioural modifications that the Infection can impose on a host include:
Lack of self-preservation when heavily infected
Nonetheless, a select number of NPCs have been shown to resist the Infection, most notably the Mantis tribe. Although how they managed to stay uncontaminated stays up to speculation, Quirrel proposes the idea that the Mantises were more intelligent or powerful than a "lesser bug".
Even once the Infection is resisted, it is still seen to have persuasive properties, as demonstrated by the outcast pack of Mantis Traitors and the Traitor Lord. After initially withstanding the effects of the plague, they relinquished their minds of their own volition due to the strength that the Infection could grant them. In the Traitor Lord's journal entry, The Hunter states:
"I have felt that desire. The desire to take the infection into myself. To become stronger, more powerful... these thoughts haunt my dreams during the darkest times. A false hope, but it can burn so brilliantly in one's mind."
It is also shown that the Infection can affect certain areas as well as creatures. The Forgotten Crossroads, at one point during the game, becomes overrun with the Infection. Large cysts and veins smother the area, blocking off certain paths and corrupting all of its enemies.
Sometime after the Pale King arrived and the Kingdom of Hallownest forgot about the Radiance, the Infection was released and spread through the dreams of bugs. Though this was caused by the Radiance, it is unsure whether this was purposeful or just an unprecedented side effect of her anger. As Moss Prophet states:
"Light is life, beaming, pure, brilliant. To stifle that light is to suppress nature. Nature suppressed distorts, plagues us."
This proposes the idea of the Radiance's light being nature, and that it will only create a plague when this nature is suppressed. It may imply that the Infection was not initially under the Radiance's control. However, this does not mean that the Radiance has nothing to do with the ruined desolation that can be seen currently. Even if the Infection was created by accident, at some point, it is suggested that the Radiance discovered how to actively use the plague as a weapon, and proceeded to use it against specific bugs to take over or twist their minds.
The Infection eventually ended up consuming the Kingdom of Hallownest. Some went mad trying to stop it, and others turned to their King who was occupied with his own methods of trying to stop the Infection. The Pale King had the idea of sealing the Radiance within the Hollow Knight. While this may have worked at first, it eventually did not prevent the Radiance from trying to exert influence. As the Infection grew, the Pale King went into hiding, and his Palace disappeared.
The Infection apparently has a sweet smell and taste.
↑Entombed Husk Hunter's Journal entry: "Inside these shambling corpses is a bright light that pierces any darkness."
↑The Radiance Hunter's Journal entry: "The plague, the infection, the madness that haunts the corpses of Hallownest..."
↑Elderbug: "Hallownest, it was once called. Supposedly the greatest kingdom there ever was, full of treasures and secrets. Hm. Now it's nothing more than a poisonous tomb full of monsters and madness."
↑ 10.010.1Furious Vengefly Hunter's Journal entry: "The infection that passes from creature to creature grants strength and courage, but it also seems to enslave the will."
↑Violent Husk Hunter's Journal entry: "First they fell into deep slumber, then they awoke with broken minds,"
↑Husk Bully Hunter's Journal entry: "It aggressively attacks any uninfected creature it finds."
↑Bardoon: "Theirs is a different kind of unity. Rejection of the Wyrm's attempt at order. I resist the light's allure. Union it may offer, but also a mind bereft of thought... To instinct alone a bug is reduced.."
↑Violent Husk Hunter's Journal entry: "Charges at enemies with no thought for its own preservation."
↑Quirrel: "They're not brutes though, no. The sickness in the air that clouds the mind of lesser beasts... they resist it."
↑Traitor Lord Hunter's Journal entry: "Embraced the infection and turned against his sisters."
↑Seer: "How fickle my ancestors must have been. They forsook the light that spawned them. Turned their backs to it... Forgot it even. And so this kingdom was born from that betrayal. But the memories of that ancient light still lingered, hush whispers of faith... Until all of Hallownest began to dream of that forgotten light."
↑Soul Tyrant: "In my dreams I could see it. The Kingdom's salvation, the cure for the plague... the answer was in the soul that animates our bodies."
↑Myla Dream Nail dialogue: "... how much longer... KILL IT... how much longer... DANGEROUS... how much longer... KILL IT... how much longer... KILL THE EMPTY ONE..."
↑Xero: "In my dreams, I would cut that plague with my nails, and then I turned my weapons upon the King."
↑Soul Master Hunter's Journal entry: "Hoarded soul hoping to stave off Hallownest's affliction, but eventually became intoxicated by its power."
↑Dung Defender: "We knights defend against the physical, but a formless enemy. How to defeat such a foe? Our King tried in his own way. A cruel means it was..."
↑Pale King: "You shall seal the blinding light that plagues their dreams."
↑Official manual:"As Hallownest fell to ruin, its reclusive king abandoned his subjects and went into hiding."
↑Relic Seeker Lemm: "Have you visited the remnants of his palace? It's down below this city, in the bedrock of the kingdom. Must've been an impressive sight in its time. Now there's nothing left. It's a strange thing though. There are no signs of conflict around the area. It's as though the whole place just vanished."
↑Volatile Mosskin Hunter's Journal entry: "The gas that seeps from their growths smells invitingly sweet, but it will burn through shell and flesh if you get too close!"
↑Husk Bully Hunter's Journal entry: "A thick orange mist fills these walking corpses. It has a sweet, sickly taste to it."
↑Wandering Husk Dream Nail dialogue: "That sweet smell...Burns..."