A distinct species derived from humans, gifted with supernatural powers and the unique ability to move in the Gloom. There are two opposing forces, called the Dark and Light Others, who are subdivided into various subspecies. They are constantly at odds with one another and actively watch for and acclimate new Others, called initiates, who share their same abilities and philosophies. To prevent a full-fledged war, the Great Treaty was signed in the 14th century. Insuring the Treaty is strictly adhered to by both sides is the primary task of the Inquisition.
Scruffy group of islanders who have wreaked havoc upon the plane-crash survivors. They kidnapped Walt, young son of Michael, but then exchanged him in a shady deal for Jack, Kate and Sawyer.