2558

February
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.
 * Fireteam Crimson uncover 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.
 * Infinity is boarded by Covenant and Promethean forces who capture Dr. Halsey. 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 he Office of Naval Intelligence, orders Captain Thomas Lasky 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.
 * Requiem is destroyed by a nearby star. The UNSC Infinity narrowly escapes.
 * Dr. Halsey joins the Covenant remnant, wanting revenge against the UNSC.

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