The 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
When compared to the general softer tones of blues and black used within the game, the Infection displays itself as a bright orange. Visually, this tone of orange can be found most commonly as the colour of an infected bug's eyes, though it can also display itself within spores and even projectiles. However, the most straightforward way to distinguish between an infected and a non-infected bug is when they are being struck, as infected bugs will release out splatters of orange blood while non-infected bugs won't.

Other more noticeable physical mutations that can be caused by the Infection include: 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 we see with Sly and Bretta. The best example would be Myla, as throughout the Knight's journey, the player can witness Myla slowly losing her mind and succumbing to the Infection.
 * Physical Bloating
 * "Natural" Adaptations ie. mushrooms on a Fungified Husk
 * Large Orange Cysts

Other behavioural modifications that the Infection can impose on a host include: Nonetheless, the Infection has been shown to be resisted by a select number of NPCs, most notably the Mantis tribe. Although how they managed to stay uncontaminated stays up to speculation, Quirrel gives us an idea that the Mantises were more intelligent or powerful than a "lesser bug". The full quote being:
 * 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
 * "The sickness in the air that clouds the mind of lesser beasts... they resist it."

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 at their own liberty due to the promising strength that the Infection could grant them. The Hunter even states:


 * "I have felt the 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 brilliantly in one's mind."

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. Embrace light! Achieve union! Oohh..Ahhh.”

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 it wanders the ruins of Hallownest. Инфекция L'Infection