Operation: WARM BLANKET was a skirmish between the United Nations Space Command and the Covenant Empire that occurred in 2544. SPARTAN-II commandos engaged the Covenant Third Fleet of Glorious Consequence and recovered Dr. Catherine Halsey from captivity.
During the Battle of Miridem, Catherine Halsey was captured by the Covenant while in cryogenic suspension as the evacuation ship carrying her was seized by the Covenant forces, leaving Halsey as the only survivor. The cryo pod was taken aboard a CAS-class assault carrier. The Covenant recognized the prisoner's value and placed decoys on escorting CCS-class battlecruisers to hamper any UNSC rescue attempts. The Covenant fleet however, became trapped in a stellar magnetic field that prevented them from jumping to Slipspace.
The UNSC used this to their advantage, and organized an Office of Naval Intelligence-led operation to rescue Halsey, who was an invaluable asset to the UNSC, and sent the ONI stealth vessel PRO-49776, commanded by Captain Lucius R. Jiron, to intercept the Covenant fleet. On board was a team of SPARTAN-II supersoldiers consisting of John-117, Frederic-104, Kelly-087, Solomon-069, and Arthur-079. The Spartans were each to utilize an Open Frame 92/Extra-Vehicular Activity, or "Booster Frame", to infiltrate the fleet and effect a rescue. Intelligence did not believe the Covenant were aware of Halsey's significance. Nonetheless, if the five Spartans failed the UNSC was prepared to liquidate the doctor by attacking the enemy fleet.
- “What we want is in the heart of this fleet - the flagship.”— John-117
The ONI ship briefly de-cloaked to launch the booster frames. Several CCS-class battlecruisers immediately engaged the Spartans with Pulse Laser Turrets, and a large inter-fleet skirmish began. The Spartans engaged and planted a scanning device on one of the ship's hull. The first scan detected a signal matching the cryo-pod's from a cruiser.
Solomon-069 and Kelly-087 immediately vectored toward the target. The pair arrived as the cruiser was launching fighters. Kelly-087 advised waiting for the other Spartans, but Solomon-069 sought to board the ship while the shields were down. Kelly-087 held the shuttle bay while Solomon-069 landed and proceeded on foot. Upon arrival at the signal's location however, Solomon-069 was met with one of the decoys - an Antimatter charge. The charge detonated, and Solomon was instantly vaporized, along the entire cruiser. John-117 thought it suspicious the scan had returned a positive match so easily but arrived only in time to warn and save Kelly-087. With scans now returning multiple decoy signatures, John-117 deduced Halsey was on the fleet's flagship.
The Covenant Supreme Commander Luro 'Taralumee initially believed all three Spartans, instead of one, had been killed by the trap and was confident the remainder would soon follow, but Major Thel 'Lodamee expressed the need for caution. 'Taralumee thought 'Lodamee's reputation tarnished by a previous inauspicious episode and was not receptive to the Major's counsel. Contrary to the Supreme Commander's optimism, 'Lodamee believed the Spartans would manage to board the flagship and prepared to face the enemy in close combat.
As the remaining four Spartans headed for the assault carrier, they were intercepted by multiple Seraph squadrons. Kelly-087's craft was severely damaged; Arthur-079 pulled back to cover them but he scraped hulls with two closely flying cruisers, lost control, and crashed. Kelly-087 abandoned her craft and took up the rear turret on Fred-104's booster frame.
The assault carrier's shields were penetrated by concentrating the fire of the booster frames' gauss cannon and missiles on the ship's port aft launch bay. The Spartans abandoned the booster frames, allowing the damaged craft to ram into the launch bay, and coasted in unopposed. Covenant troops were already mustered in strength to repel the boarders. A short lull occurred as the three remaining Spartans sheltered under a Bubble Shield and prepared to sprint for the target.
- “Look's like this is the right ship. ”— Fred-104
- “We' got three minutes.”— Kelly-087
- “Let's sprint this, don't fall behind.”— John-117
- “Copy that.”— Kelly-087 and Fred-104
The relentlessness of the Spartans' attack shocked the Fleet Master. They broke out of the hanger and into the corridor beyond at speed, firing at anything in the way. Fred-104 destroyed sealed hatches and bulkheads with a Spartan Laser.
Fighting through multiple Jiralhanae, Kig-Yar and Unggoy, the Spartans were ambushed by Thel 'Lodamee and two other Sangheili wielding energy swords. Kelly-087 sprinted past the Sangheili completely. Fred-104 stabbed one in the head with a combat knife and then grappled with 'Lodamee, allowing John-117 to disengage and catch up with Kelly-087. Fred-104 remained behind with knives to delay the two remaining Sangheili.
The Fleet Master became desperate and began detaching sections of the ship to stop the enemy advance. The Spartans scrambled through zero-g and vacuum to reach the closing airlock beyond the detaching block. At the last stretch of vacuum, Kelly-087 transferred her momentum to John-117, propelling herself into space, but John-117 entered the airlock just before it closed and proceeded to the objective alone. Seeing that the Spartans had scaled over half of the 3 mile long craft with 3 minutes remaining, they would have had to been moving at a speed of around 20-25 mph the entire time, a profound demonstration of their superhuman speed.
John-117 moved through the ship, found Halsey's cryo-tube, and enjoyed a brief reunion after thawing her out. 'Lodamee intercepted the pair as they made to leave the ship. The Major gave the Spartan an energy sword and they duelled, with the Sangheili disarming his opponent after several seconds. However, at the same time, the fleet had cleared the stellar magnetic field and the Fleet Master was eager to jump immediately, assuming that 'Lodamee had failed his task. The Fleet Master detached and set the self-destruct for the entire ventral aft section of the ship, hoping to kill John and Halsey in the process. An incensed 'Lodamee was involuntarily lifted to safety by gravity lift before he could kill the Spartan.
John-117 and Halsey abandoned ship in an escape pod. Seraphs appeared to pursue the slow and unarmed pod. Kelly-087 and Fred-104 escaped in commandeered Seraphs and covered the pod. The ONI stealth ship returned to drive off the remaining pursuers and recover Halsey and the Spartans.
Back on the stealth ship, John-117 lamented the loss of Solomon-069 and Arthur-079 and noted Thel 'Lodamee's abilities. Halsey agreed improvement was necessary and predicted the war was far from over.