2401 Penitent Tangent

"Greetings! I am 2401 Penitent Tangent. I am the monitor of Installation 05."

- 2401 Penitent Tangent introducing himself to John-117 and Thel 'Vadamee

05-2401 Penitent Tangent was the monitor of Halo Installation 05.

Biography
2401 Penitent Tangent, as well as the other six monitors, was present at the dispersion of the activation indexes prior to the firing of the Halo weapons near the end of the Forerunner-Flood war.

Penitent Tangent was charged with regularly scheduled communications with the other Halo array monitors for updates. Several millennia after the rings were fired, though, he ceased sending these messages. Penitent Tangent was the last monitor to send a message to 343 Guilty Spark on Installation 04, though Guilty Spark described his final messages as "incomplete and quite perplexing," and logged his concerns about Penitent Tangent's ability to perform his duties, believing he had not been functioning correctly for some time before his messages ceased.

Flood outbreak
In May 97,227 BCE, another artificial intelligence construct warned 2401 Penitent Tangent of a pending outbreak in one the installation's Flood containment facilities. The monitor continued to ignore this warning, and those that followed, for millennia. Within 99,779 years, the containment facility had been overrun by the Flood, with lockdown protocols in effect within the Halo's teleportation grid to prevent further infestation. Eventually, the Quarantine Zone was established and the full force of the installation's Sentinels and Enforcers was mobilized.

Battle of Installation 05
"And you know nothing about containment! You have demonstrated a complete disregard for even the most basic protocols!"

- 2401 Penitent Tangent rebuking the Prophet of Regret

By November 2, 2552, 2401 Penitent Tangent had been captured by the Flood and was held captive by the Gravemind that had manifested on Installation 05. After the battle on the ring had raged for some time, the Gravemind absorbed and reanimated the Prophet of Regret, one of the Hierarchs of the Covenant. Later, Spartan John-117 and Arbiter Thel 'Vadamee were also captured by the Gravemind. Upon seeing John, a Reclaimer, the monitor urged the Spartan to activate the ring. This was immediately objected to by Regret, who insisted that nothing could be done until he had completed his sermon in preparation for the Great Journey. The monitor countered that the installation had a firing record of 1.2 trillion simulated, and one actual thus making the ring fully prepared to fire on demand. The Hierarch then retorted that the "Oracles" were the most worthless artifacts that had been left by the Forerunners, prompting the monitor to berate Regret for his lack of regard for protocol. Amid the argument, the Gravemind insisted that the four factions represented in the meeting shared a common goal: preventing the ring from being activated. Shortly thereafter, the Gravemind used the monitor's control of Installation 05's teleportation grid to send the Spartan to High Charity and 'Vadamee to Halo's control room, respectively, in an attempt to stop the activation of the Halo array. The current status of 2401 Penitent Tangent is unknown.

Trivia

 * 2401 Penitent Tangent was voiced by John Michael Higgins.
 * Like all monitors, 2401 Penitent Tangent's numerical designation is derived from seven raised to one less than the number of his installation (7n-1). This is one of Bungie's numerous references to the number seven in the Halo series.
 * "Penitent" means feeling or expressing sorrow for sin or wrongdoing and [being] disposed to atonement and amendment" and is synonymous with "repentant". "Tangent" is part of the idiom "off on a tangent", which refers to digressing suddenly from one course of action or thought and turning to another.
 * 2401 Penitent Tangent appears in the Halo 2 multiplayer map Backwash. He hovers around the map and is invulnerable to damage.

List of appearances

 * Halo 2
 * Halo 3
 * Bestiarum
 * Halo: Combat Evolved Anniversary
 * Terminals
 * Halo 2: Anniversary
 * Halo Mythos: A Guide to the Story of Halo