Warhammer 40k: Imperial Agents - Navigator
A Navigator (Homo navigo) is a very particular form of Imperial-sanctioned Human mutant who possesses the Navigator Gene. This gives a Navigator the unique ability to navigate a faster-than-light starship accurately through Warpspace to emerge safely at another point in realspace. This ability makes Navigators absolutely essential to the Imperium's continued survival and to all Human interstellar transportation, communication and commerce.
All Navigators have a third eye, commonly called the "Warp eye," on their foreheads, which allows them to perceive the "psychic light" projected by the Emperor from Terra known as the Astronomican, enabling them to fully use their powers in guiding Human starships through the currents of the Warp.
Their ability to sense the tides of the Warp is considered a psychic power, although Navigators never possess any psychic abilities beyond the powers their Warp Eye affords them.
Navigators possess natural life spans of as much as four hundred Terran years. As they increase in age, their abilities increase in power, and their physical appearance changes: the white and iris of the third eye gradually disappear, leaving only a hardened black orb.
All Navigators belong to a large group of noble families based on Terra in the great district of that world-city known as the Navigator's Quarter. These dynasties are known collectively as the Great Families of the Navis Nobilite.
