2558

February
February 6
 * Gabriel Thorne becomes an official member of the SPARTAN-IV Program and is assigned to the Fireteam Majestic.

February 8
 * returns to Requiem to establish research facilities on the shield world. Commander Sarah Palmer, leader of the Infinity ' s Spartan contingent, sends various Spartan teams, notably Fireteam Crimson and Fireteam Majestic, to the surface of Requiem. Marine, Army, and Navy assets are also deployed.

Unknown date
 * Spartan Fireteam Crimson uncover a Forerunner slipspace artifact. After the device teleports Chief Engineer Glassman to the surface of the planet, Dr. Catherine Halsey is brought in to investigate.
 * The artifact scans the ship's systems and begins transmitting data to the surface of Requiem, where said data is intercepted by Jul 'Mdama. Glassman is taken captive by the Covenant and is ordered to activate the Librarian's shrine, though he is not successful.
 * Sangheili terrorist Parg Vol is assassinated by Fireteam Crimson.
 * Fireteam Crimson secure another Forerunner artifact, dubbed "the Didact's Gift". This device contains the memories of victims of the Didact's attack on New Phoenix six months prior. The processed human minds are to be repurposed as Promethean Knights. Spartan Gabriel Thorne is translocated to the Cauldron by the first artifact.
 * Dr. Halsey begins dialog with an unknown party who shares her interest in the Librarian. The intelligence is actually Jul 'Mdama, the Covenant's leader, who is manipulating Halsey into divulging vital secrets about the Forerunners. Halsey is apprehended after her unwitting communication with 'Mdama is discovered. Spartan Thorne rescues Dr. Glassman and the pair escape custody.
 * Dr. Halsey learns that John-117 is still alive. The Infinity is boarded by Covenant and Promethean forces who capture the doctor. They take her to the Librarian's "shrine", where 'Mdama awaits.
 * Gek, 'Mdama's lieutenant, is killed by Fireteam Majestic.
 * Admiral Serin Osman, head of the Office of Naval Intelligence, orders Captain Thomas Lasky to kill Dr. Halsey. Commander Palmer is to execute the order.
 * Lasky sends Fireteam Majestic to rescue Dr. Halsey and stop Palmer.
 * The Librarian gives Dr. Halsey the Janus Key, but Jul 'Mdama gets half of the key. Halsey gives Gabriel Thorne the other half before she is taken away.
 * Jul 'Mdama sends Requiem on a collision course with its sun, Epoloch. While the shield world is destroyed, the UNSC Infinity narrowly escapes the planet's slipspace conduit.
 * Dr. Halsey agrees to cooperate with Jul 'Mdama and his forces, stating that she wants revenge.

March
March 3 March 5
 * Captain Lasky and Commander Palmer are debriefed by the UNSC Security Council at HIGHCOM Facility Bravo-6. The committee expresses misgivings of Lasky's handling of the Second Battle of Requiem and the failed assassination and escape of Dr. Halsey. Lord Terrence Hood later tasks Infinity to escort him and the Arbiter on a diplomatic mission to Ealen IV.
 * Infinity arrives at Ealen IV. Lord Hood meets with Thel 'Vadam and the Jiralhanae Chieftain Lydus. While negotiating, the delegates come under attack from the Guardians of the Righteous. The SPARTAN-IV's defend the Ambassadors.

Trivia
This time frame is the setting for the first season of Halo 4's Spartan Ops mode.