Spartan Ops

Spartan Ops is a cooperative mode in Halo 4 which succeeds Firefight from Halo 3: ODST and Halo: Reach. It is made up of ten episodes which contain five chapters each. Each episode is accompanied with a short CGI movie which explains the story. The story takes place 6 months after the events of the Halo 4 campaign and mainly revolves around Fireteam Crimson, a team of SPARTAN-IVs deployed on the shield world Requiem.

Unlike in the Campaign, players' customized loadouts are available for each Spartan Ops mission and playing gives players XP towards their next rank. Players work as part of a team of Spartan IVs known as Fireteam Crimson and perform various types of objectives, including eliminating all enemies, destroying key targets, or activating consoles to progress.

Spartan Ops supports a maximum of 4 players and requires an Xbox Live Gold Membership to play.

Season 1 Episode 1
In February 2558, 6 months after John-117 defeated the Didact, UNSC Infinity, led by Captain Lasky, recalls the entirety of her SPARTAN-IV contingent for deployment to the Forerunner world Requiem. Fireteam Majestic is met by Infinity's AI Roland and abruptly becomes aware of their new Commanding Officer before being led to their living quarters. Infinity engages the Covenant Remnant Fleet straight out of Slipspace deploying frigates and SPARTAN teams into Requiem.

In-game events
In February 2558, SPARTAN-IV Fireteam Majestic along with several other Spartan IV teams arrive onboard UNSC Infinity, which departs for Requiem. Once there, Infinity engaged in combat with the Storm Covenant fleet, and deployed ground forces, including Fireteams Castle, Majestic, Domino, Ivy and Crimson as well as detachments of Marine, Army and Navy forces on the planet. Fireteam Crimson ran through a series of search and destroy, rescue, artifact recovery, extraction and assassination ops. Spartan Jared Miller was responsible for Crimson's ops with Spartan Robert Dalton in charge of ordnance, airstrikes and extraction. Commander Sarah Palmer occasionally stepped in as she deemed Crimson to be the squad of choice to deploy into the most dangerous ops. Before being extracted from their op, a large detachment of the Covenant Remnant forces including a Covenant cruiser, Banshees and several Phantoms surrounded Crimson and captured them, taking them to an unexplored Forerunner structure.

Season 1 Episode 2
After the recovery of a Forerunner Artifact by Fireteam Crimson, upon transporting the artifact, it activates creating a scan of Infinity's systems causing a loss in most of the power and gravity. The Infinity began falling into Requiem's opening until Commander Sarah Palmer uses 'physical persuasion' on the artifact granting power to the Infinity and its engines. Dr. Glassman inspects the artifact only to be pulled into it shortly after.

In-game events
Set sometime after Part 1, Spartan IV Fireteam Crimson are held prisoner by the Covenant Remnant. Spartan Miller and UNSC Infinity's AI Roland manage to track Crimson's location. Spartan Robert Dalton orders a diversionary airstrike allowing Crimson to break free and kill their captors. During their escape they meet with MIA Icebreaker squad led by Lieutenant TJ Murphy who hacks an enemy Phantom allowing Crimson and Icebreaker to escape. Crimson then participate in Ops far beyond enemy lines due to the Covenant Remnant believing the captured Phantom to still be one of theirs. Crimson is then directed to sabotage and gather intelligence similar to what they were usually assigned before their capture.

Trivia

 * By completing all the Chapters from Departure on Legendary, the achievement A Legendary Episode is unlocked.
 * Some missions have a Red vs. Blue audio easter egg that can be activated by shooting a hidden radio. Shooting the radio causes the Red vs. Blue opening theme song to play and the Roses Vs. Violets achievement to unlock.
 * A number of the maps in Spartan Ops are reused maps from the Campaign or War Games.
 * Episodes 1-5 are contained in the second disc of the Halo 4 game. Episodes 6-10 are available as free downloadable content on the Xbox Live Marketplace.
 * The additional content from the August 19 Title Update (which includes content purchased in the Champions Bundle) is not available in Spartan Ops.