Operation: SILENT STORM

Operation: SILENT STORM was a UNSC Operation against the Covenant early in the Human-Covenant War aimed at buying humanity time to develop effective countermeasures against Covenant technology. It was comprised of a series of engagements featuring mainly the SPARTAN-IIs and 21st Space Assault Battalion.

Attack on Harvest
In 2525, the Covenant declared war on humanity for supposed heresy and defilement of Forerunner relics. The first engagements took place on the colony world Harvest, with Sergeant Avery Johnson leading Colonial Militia forces against the Jiralhanae of Maccabeus' clan. During the engagement, Sergeant Johnson led a boarding action of the Kig-Yar vessel Minor Transgression. The resulting skirmish led to the Marines boarding and almost capturing the vessel prior to its self-destruct.

Following this first attack on Harvest, Vice Admiral Preston Cole led a massive attack aimed at recapturing the world from the aliens. Using the largest-ever assembled fleet in human history, the Admiral won victorious over the aliens, but at extremely heavy losses. This battle was soon followed by more Covenant attacks at other colony worlds including Chi Ceti IV and Alpha Corvi II, and the start of the five-year Harvest campaign.

UNSC Planning
With the initial reconquest of Harvest successful at a high price, it became clear to UNSC command that the war was unlikely to be one through sheer naval superiority due to the aliens' vastly superior technology. Realising the UNSC needed time to fully mobilise for war and to develop technology sufficient of fighting the new threat, Vice Admiral Cole convened a meeting to devise Operation: SILENT STORM. Inspired by Sergeant Johnson's successful boarding of Minor Transgression and the successful boardings of Unrelenting and Radiant Arrow by SPARTAN-IIs the year prior, Cole intended to use the SPARTANs supplemented by an ODST space assault battalion to infiltrate and plant nuclear weapons on Covenant vessels and staging points behind enemy lines - disrupting the enemy supply lines and invasion while the UNSC could prepare.

The plan called for three teams of SPARTAN-IIs - Blue, Gold and Green - to lead the 400-strong 21st Space Assault Battalion in boarding as many Covenant vessels as possible. The operation would be enabled by a task force of Prowlers - Task Force Yama. Using the stealth craft, the operation was given free reign to approach its goals however it saw fit, operating within enemy territory without support or communications. To assist the SPARTANs in working alongside UNSC personnel and to provide advice and assistance, Sergeant Johnson was additionally brought onto the operation in an advisory role.

Following the predicted enemy attack patterns, the UNSC estimated that the next colony world in the Covenant conquest would be Biko. Task Force Yama would covertly infiltrate Bikon airspace and land in a deserted ice quarry on the moon of Seoba and wait until the Covenant had engaged regular defensive forces in orbit before infiltrating unnoticed amidst the chaos. Depending on the outcome, the distracted Covenant fleet would then be beset upon by Cole's Battle Group X-Ray or destroyed by the SPARTAN infiltration.

Insurrectionist plot
With the Covenant invasion of the outer colonies strong, the Insurrectionists hoped to spare their worlds by aligning with the aliens to fight against the UNSC - unaware of the aliens' genocidal intent. Lyrenne Castilla called for a conference aboard her frigate Bellicose, consisting of the leaders of a number of rebel cells. The groups invited to the conference included the United Rebel Front, Gao Liberation Force, Biko Independence Army, Venezian Militia, Freedom League and People's Occupation. Here, the group discussed plans to ally with the aliens and drew up a plan. The Gao Liberation Force (GLF), represented by Petora Zoyas and wanting to increase its influence, divulged its knowledge of Operation: SILENT STORM and the imminent attack on Biko - knowledge gleaned from the group's spy within Task Force Yama. The Biko Independence Army (BIA) was outraged by the UNSC plan to use Biko as a "sacrificial lamb", and demanded immediate action. Hoping to use the Covenant to attack the UNSC and destroy the SPARTAN supersoldiers - who had been successfully rooting out the Insurrection for years - the rebels would present this knowledge to Covenant, with the promise of more to come on the condition that Biko and other rebel-aligned worlds be spared from the onslaught.

Meanwhile, the other insurrectionist groups would pledge their aid to the Bikon insurrection; using the ice quarry at Seoba as a base, the combined force would strike at Biko's orbital facilities and government, overwhelming the planetary defenses ready to offer the planet to the Covenant when the attack came. The information was presented to Silent Shadow operative Tel 'Szatulai upon notice, who promptly brought the information to Nizat 'Kvarosee, the fleetmaster or the Fleet of Inexorable Obedience. 'Szatulai and a force of Bloodstars were dispatched to the Seoba quarries to meet with the insurrectionists and gain their knowledge, before promptly wiping them out.

Battle of Seoba
Upon arriving at Biko's third moon of Seoba, Task Force Yama soon realized that the moon was the Insurrectionist staging ground for their coup. Trying to land ODSTs on the moon’s quarry through aerial drops, the UNSC force suffered severe losses, with one company of the 21st Space Assault Battalion taking over 30% casualties, although three Spartan-II teams (including Blue Team) were able to stop the Insurrectionists from reporting news of the attack to their superiors. After taking several hundred Insurrectionist prisoners, who Colonel Marmon Crowther put in the hands of the Spartans to guard while the ODST battalion withdrew to orbit. John-117 was able to find former UNSC Major General Harper Garvin among the prisoners. It was then that a flotilla of Covenant stealth ships, led by Blademaster Tel 'Szatulai, visually spotted seven UNSC Prowlers and engaged their larger force in an attempt to capture one of the superior UNSC stealth ships. In this engagement, Captain Halima Ascot was killed when her prowler, UNSC Starry Night, was downed and crashed near the Seoba Ice Quarry. Blue Team were able to make their way to the crashed Starry Night and activate its onboard Fury tactical nuclear weapon to destroy the prowler and sensitive information on its data logs, including, among other things, the location of Earth. During the battle, Commander Hector Nyeto attempted to get the Spartans killed by delaying an attack run on the Covenant ships, but all Spartans survived and two more Covenant ships were eventually destroyed by Nyeto’s squadron.

List of appearances

 * Halo: Silent Storm
 * Halo: Oblivion
 * Halo: Shadows of Reach