Infection

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:
 * Physical bloating
 * 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: 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. The Hunter states:
 * The loss of their will
 * Fragmenting of their mind
 * Tendencies to attack non-infected bugs
 * Linking up to the hive mind of The Radiance
 * Increase in strength and courage
 * Lack of self-preservation when heavily infected


 * "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.

History
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. Now the infected bugs and citizens of the fallen Kingdom make up nearly all of the "life" that greet the Knight as they wander the ruins of Hallownest.

Trivia

 * The Infection apparently has a sweet smell and taste.

Чума L'Infection