Retriever Sentinel: Difference between revisions

|role=Construction and mining<ref name="EVG">''[[Halo: The Essential Visual Guide]]'', p. 167</ref>

|length=Slightly smaller than 478 meters<ref name="hitd103">''[[Halo: Hunters in the Dark]]'', Chapter 6</ref>

|armament=*Gravitic beam<ref name="hitd103"/>

{{Quote|It's a '''Strato-Sentinel'''. It's one of the automated drones the Forerunners use on their artificial worlds. The Covenant originally thought them to be holy warriors of the Sacred Rings. There are many types of Sentinels that the Forerunners created—this particular one is designated as a '''Retriever'''.|[[Usze 'Taham]]<ref name="hitd103"/>}}

The '''Retriever Sentinel''', is a variant of [[Strato-Sentinel|Strato-]][[Sentinel]] drones employed by the [[Forerunner]]s. Considered to be one of the more powerful variants of the Sentinel, Retrievers are massive, ship-sized drones that were utilized to construct installations of the [[Halo Array]] from [[Installation 00]], as well as to provide maintenance to the Ark itself.<ref name="hw2">''[[Halo Wars 2]]''</ref><ref name="pl retriever">'''Halo Wars 2''', ''[[Phoenix Log]]: Retriever Sentinel''</ref>

{{Quote|Our records indicate that it employs an artificially produced gravitic force to remove minerals from a planet's surface. Those minerals in turn are used to build Forerunner structures and installations.|Usze 'Taham, referring to the Retriever Sentinels<ref name="hitd103"/>}}

A Retriever is capable of producing an [[Artificial gravity|artificial gravitic force]] that allows it to remove materials from a world's surface. Once in position above an acceptable place to harvest, the Retriever deploys its blue, gravitic beam towards the world's surface and begins hauling chunks of land caught in the beam into its underbelly.<ref name="hitd103"/> The mining process utilized by a Retriever is noted to create a tornado-like effect as the ground is pulled into the Sentinel's hold.<ref name="hitd272"/> If deemed necessary, a Retriever is capable of connecting and merging with another Retriever and forming a single unit. Combined Retrievers somewhat resemble an average Retriever, though they seem to be more effective in combat and are significantly more maneuverable. With no apparent drawbacks, a combined Retriever seems to take on the benefits of both Retrievers' speed and weaponry.<ref name="hitd122">'''Halo: Hunters in the Dark''', ''pages 122-126'' (Google Play edition)</ref>

When a Retriever is threatened or attacked, these Sentinels may use their gravitic beam as a dangerous and highly destructive,<ref name="pl sentinel">'''Halo Wars 2''', ''Phoenix Log: Forerunner Sentinels''</ref> though cumbersome, weapon. As the Sentinel was not designed for combat situations,<ref name="hitd107">'''Halo: Hunters in the Dark''', ''pages 107-108'' (Google Play edition)</ref> Retrievers have little to no shielding.<ref name="hitd272"/> In [[2555]], [[monitor]] [[000 Tragic Solitude]] outfitted thousands of Retrievers with massive energy weapons mounted on their fronts.<ref name="hitd122"/> These weapons are similar in design to the [[Sentinel beam]]s employed by the smaller [[Aggressor Sentinel]]s.<ref name="pl retriever"/> These Retrievers were capable of utilized powerful volleys of energy against opponents and were significantly faster and had greater maneuverability in space.<ref name="hitd122"/> Once destroyed, Retrievers typically exploded into a giant fireball that engulfed its surroundings.<ref name="hitd118"/>

The Retrievers are among the most powerful of the [[Sentinel]]s employed by the [[Forerunner]]s,<ref name="pl retriever"/> with their primary purpose being the mining, gathering, and transporting of minerals and other natural resources from a world.<ref name="hitd118"/> Using its artificially created gravitic force, Retrievers extract materials from a world's surface and transport to construct Forerunner structures and installations.<ref name="hitd103"/>

The Forerunners utilized Retrievers to help in the maintenance of [[Installation 00]].<ref name="pl retriever"/> The Retrievers employed at the Ark worked with [[Assembler Sentinel]]s to construct new installations. Populating the [[Foundry]],<ref name="pl sentinel"/> Retrievers mined and gathered raw materials from the planetoid hosted in Installation 00's center and transported them to a forge within the Foundry that refined, processed, and stabilized the materials into the mold of a Halo installation.<ref name="hitd246">'''Halo: Hunters in the Dark''', ''page 246'' (Google Play edition)</ref> The Assemblers would then use these resources to build components of the installations.<ref name="pl foundry">'''Halo Wars 2''', ''Phoenix Log: The Foundry''</ref> Although usually automated, Retrievers can be controlled by a [[monitor]]. Monitors are capable of effectively utilizing Retrievers in combat, and can have them overwhelm opponents.<ref name="hitd122"/>

After the [[Battle of Installation 04|destruction]] of [[Installation 04]] on [[2552#September|September 23, 2552]], Retrievers on Installation 00 began to mine the planetoid captured in the Ark's [[Foundry]] to construct [[Installation 08|a replacement installation]]. On [[2552#December|December 11, 2552]], these Retrievers were encountered and observed by [[Sangheili]] and [[United Nations Space Command]] forces during the [[Battle of Installation 00]].<ref name="hitd103"/> The battle ultimately resulted in the Ark becoming heavily damaged, leading to [[000 Tragic Solitude]]—Installation 00's now-[[Rampancy|rampant]] [[monitor]]—allocating all of his time and resources to the construction of thousands of heavily armed Retrievers that would mine [[human colonies]] for resources to repair the Ark, blaming humanity for damaging his installation.<ref>'''Halo: Hunters in the Dark''', ''page 259'' (Google Play edition)</ref>

{{Quote|When we first arrived here, the Ark had suffered great wounds from our war against the Covenant, and so we activated dormant Retriever Sentinels and deployed them to strip-mine lifeless planets for the materials needed to repair the installation. Like watching a sleeping giant nudged into wakefulness, the reconstruction slowly reached full automation until we were no longer needed to guide the Sentinels and could simply sit back and record the wonder of a world being reborn.|[[Nathaniel Palmer|Nathaniel J. Palmer]], an archaeologist of Henry Lamb Research Outpost<ref name="old wounds">'''Halo Wars 2''', ''Phoenix Log: The Healing of Old Wounds I''</ref>}}

Doctor [[Luther Mann]] theorized that the dormant Retrievers could be reactivated and utilized to repair the Ark, opening slipspace portals to strip-mine uninhabited planets for the resources and minerals required to repair the Ark.<ref name="hitd361"/> In [[2557]], a human research team traveled to Installation 00 aboard ''[[Eden Rising]]'' to establish a permanent base on the Ark, the [[Henry Lamb Research Outpost]]. Desiring to repair the installation, the researchers activated the dormant Retrievers,<ref name="pl henry lamb">'''Halo Wars 2''', ''Phoenix Log: Henry Lamb Research Post''</ref> under the guide and direction of the [[smart AI]] [[Isabel]]. To gain resources, the Retrievers were deployed to strip-mine lifeless planets. Before long, the Retrievers were able to enact repairs unsupervised,<ref name="old wounds"/> leading to Isabel and the researchers setting to the task of cataloging and analyzing the installation.<ref>'''Halo Wars 2''', ''Phoenix Log: Isabel''</ref> The Retrievers acted quickly and within months had largely restored the Ark to its former state,<ref name="pl retriever"/> as well as constructing another [[Installation 09|replacement Halo installation]] at the Foundry.<ref>'''Halo Wars 2''', campaign level, ''[[From the Deep]]''</ref>

However, in [[2558#October|October 2558]], the portal to the Ark had shut down again with the [[Banished]] arriving at the installation in the following month. The human researchers were killed by the Banished, while the Retrievers sought to defend their installation from the hostile invaders who were attempting to appropriate the installation for their own purposes.<ref name="pl retriever"/> In [[2559#March|March 2559]], {{UNSCShip|Spirit of Fire}} arrived over the Ark, where the ship's crew soon came into [[Second Ark Conflict|conflict]] with the Banished. During the resulting battle, UNSC forces managed to access the replacement Halo installation, having it depart the Ark's Foundry. In response, heightened automated security protocols were initiated and Retrievers were deployed to repel the invaders. While Banished and UNSC forces battled on the surface of the new Halo, a Retriever attacked forces from both sides. After UNSC forces managed to damage the Sentinel, the Retriever retreated for repairs. With UNSC forces taking control of three nearby control towers, Professor [[Ellen Anders]] of ''Spirit of Fire'' soon found a way to manipulate the Ark's command codes and bypass directive locks, allowing her to take control of the Retriever. The UNSC used the Retriever to disable a nearby [[energy barrier]], giving them access to the Halo's [[control room]].<ref>'''Halo Wars 2''', campaign level, ''[[The Halo]]''</ref>