Primordial

"We meet again, young one. I am the last of those who gave you breath and shape and form, millions of years ago. I am the last of those your kind rose up against and ruthlessly destroyed. I am the last Precursor. And our answer is at hand."

- The Prisoner speaking to the Didact.

The Prisoner of Charum Hakkor, also known as The Timeless One was an individual of great power detained on Charum Hakkor. Unbeknownst to most of the galaxy, this individual was in fact the last living Precursor.

History
The creature was discovered by humans after they colonized Charum Hakkor, contained within a capsule of Precursor origin. Despite the advanced nature of Precursor technology, the humans managed to find a way to communicate with the captive for brief periods of time. They came to regard the creature within the cell as an oracle of sorts, asking it questions in the hopes of gaining greater understanding. Most of the time, the prisoner's answers were confused or unintelligible.

When the Flood first made an appearance in the Milky Way, several humans questioned the prisoner as to the nature and origin of the "disease". When the prisoner gave them an answer, the humans present were so deeply horrified that many of them committed suicide. Following the end of the Human-Forerunner wars, the Didact and a group of Prometheans gained access to the Prisoner. It told the Didact that it was the last Precursor, and that the Forerunners had rebelled against the Precursors. The Didact told none of this to any, save the Librarian.

When Mendicant Bias tested a Halo in the Charum Hakkor system, the Halo's energies shattered every Precursor structure on the planet, freeing the prisoner. Its whereabouts following its escape are unknown, though it is suspected that the Precursor may have stowed away on Mendicant Bias' Halo ring.

Trivia

 * He is thought to have escaped on the Halo that was test-fired at Charum Hakkor 'four to five decades ago', which Mendicant Bias took into slipspace and hid until his return under 'a new master'. The Gravemind, according to the Halo 3 terminals, talked with Mendicant for 379,807 hours, or roughly 43 years, before Bias agreed to fight for him.  It is unknown how the two are linked, however.

List of appearances

 * Halo: Cryptum