The quarantine shield was a Dyson sphere, more specifically a variation of the concept known as a Dyson swarm, composed of trillions of vigilants, formed by the Forerunners around the San'Shyuum quarantine system following the San'Shyuum's surrender in the human-Forerunner wars. Extending four hundred million kilometers from the system's star, the region inside the shield included the San'Shyuum homeworld Janjur Qom as well as another major planet inhabited by the species. The quarantine shield required special access codes to pass through, and if the San'Shyuum population showed signs of unrest, the shield would enter "battle mode", heightening the vigilants' combat readiness.
List of appearances
- Halo: Cryptum (First appearance)
- Halo: Cryptum, page 144
- Halo: Cryptum, page 170