Cheriton's Viper Incident

The Cheriton's Viper Incident, also known as the Parapet Incident, were a pair of minor engagements between the UNSC and the insurgent Outriders. It was remembered because of the UNSC's massacre of hundreds of Arcadian civilians.

Background
The Cheriton's Viper was the name of a convoy escort purchased by a warlord on Arcadia following the Covenant's initial attack on the planet. It spent the next sixteen years patrolling the Procyon system, keeping out the worst of the pirates even as Arcadia descended further into lawlessness. When the Covenant returned in 2549, it escorted a flotilla of evacuation ships out of the system.

This flotilla wandered about the Human Sphere for another two years, where concerns over the UNSC's ability to win the war eventually led to the creation of the Outriders. They believed that humanity's best chances of survival laid in escaping into deep space, and simply putting as much distance from the Covenant as they could. Supplies were collected and stored, vital technical skills were studied and shared around, and at times they raided military warehouses for defensive arms.

Battle
In December 2551, while the refugee fleet stopped over in the Beta Comae Berenices system, the Cheriton's Viper sounded a distress signal. The UNSC Upon the Parapet, a Charon-class frigate, responded and approached the stricken ship to provide assistance. As it docked, it was attacked by a boarding party that overwhelmed its skeleton crew and captured the frigate. Afterwards, over 1,000 civilians were moved into its hangar bay, and the convoy departed with its new prize.

The Parapet managed to regroup with other Outrider vessels, and was preparing to depart the Human Sphere when they were intercepted in the Diadem system by the UNSC Feeling Lucky. A short battle ensured which ended with the Parapet disabled and boarded by the cruiser, who were under orders to recover the frigate intact. The presence of civilians made the subsequent ODST assault long and bloody. Eventually, the ship was recaptured and prisoners and civilians were offloaded onto the cruiser.

Although naval personnel were sent to repair the frigate, it was subsequently destroyed when nuclear scuttling charges planted by the Outriders detonated. In retribution, a handful of ODSTs opened the airlocks of several compartments filled with civilians and prisoners, spacing over 500 people. What remained of the frigate was tagged for later salvage.

Aftermath
Following the Incident, the UNSC conducted an investigation that ultimately saw most of the involved personnel being demoted and transferred to Reach to carry out their probations. Though the whole affair was quietly buried and classified, an ODST nicknamed "Angel" leaked it to the public, and condemned the lack of justice that was dealt. Afterwards, a number of sailors and civilians in other compartments spread rumors of bodies tumbling past the viewports. A few even stated that they heard gunshots, though this was often disregarded, given that spacing would kill them anyway.

The event drove a wedge between the UNSC and various Outer Colonial populations. In the UNSC's case, they simply couldn't believe that there were still extremists that were willing to betray their trust and the loss of even a lowly frigate cost them a significant resource in their fight against the Covenant. However, it was later discovered that the captain of the Viper had worked alone: even his allies in the Outriders were shocked at what he did. Still, the fact that the massacre happened at all, coupled with the minor punishments dealt, reflected that the age-old belief that the UNSC cared little about the colonists.

Alleged Coverup
The initial act of piracy is uncontroversial. The UNSC formed an inquiry, and the findings match with testimony from crewmembers of the Cheriton's Viper, who left the ship shortly after the piracy to avoid any reprisals from the UNSC. Likewise, the boarding and recapture of the Upon the Parapet is fairly well-documented from the testimony of the surviving civilians. The only point of controversy is the events on the UNSC Feeling Lucky that led to hundreds of civilians flying out an airlock.

The initial report from the Feeling Lucky, which was repeated uncritically in the Navy's press release, was that hundreds of civilians were detained in dropship hangars until habitation modules could be prepared for them. The blast from the nuclear scuttling charges drove shrapnel through the two starboard hangar bays. The integrity of the bay doors was compromised, and they opened to vacuum, killing all inside except for ODSTs in EVA gear. This conflicted sharply with scuttlebutt from the midshipman grapevine, which held that the doors were opened manually, and other compartments heard gunfire.

Accusations of a coverup were quickly raised, although colonial groups themselves were split on the issue. These accusations simmered until July 2552, when leaked files blew the incident wide open. The mission record of an ODST, a Sergeant Alfonzo Hernandez, was passed to a number of colonial groups. These records showed that the hangar doors in Bay Two only suffered light damage from the shrapnel. Additionally, a civilian woman, an infant, and an ODST from Bay One received treatment in the medical bay, the latter suffering from three gunshot wounds and a near-overdose on stimulants.

Rough Timeline of the Hernandez Record:
T+ 00:00: Boarding craft launched from the UNSC Feeling Lucky, impact the Upon the Parapet four minutes later.

T+ 00:08: Airlock breached, ODSTs pile into the frigate and storm the bridge. The hangar bay is cut off from the rest of the ship.

T+ 00:31: Bridge taken, surviving Outrider crew retreats to Engineering. Outrider soldiers from the hangar bay attempt to catch Hernandez's squad from behind.

T+ 00:41: Hernandez's squad meets up with a squad led by Lieutenant Angelica Chaisson. A team of combat engineers is called forward, and the siege of the engineering compartment begins.

T+ 03:01: After two hours, under sporadic attack from Outriders moving through the maintenance hallways, the engineers breach the bulkhead and the troopers move in. Casualties are heavy. All Outrider crewmen in the Engineering compartment are killed, including the former captain of the Cheriton's Viper. ODST casualties are two wounded, five dead.

T+ 03:18: A new platoon of ODSTs and combat engineers board the Upon the Parapet to perform a final security sweep and prepare the Frigate to travel back to Reach. Hernandez's and Chaisson's squads return to the Feeling Lucky with the last of the civilians from the hangar.

T+ 03:27: Upon arriving in Bay Two, Hernandez's squad is tasked with watching over 350 civilians. ONI analysts and security troops are already tied up dealing with hundreds of other civilians in Bay Three and Four. By implication, Lieutenant Chaisson's squad arrived in Bay One. Hernandez's squad guards the civilians as two sailors pass among them, identifying each Outrider with a biometric scan.

T+ 03:40: The Upon The Parapet, which is visible through the hangar doors, vanishes in a flash of light. The tension in the hangar rapidly escalates as ODSTs shout at the civilians and the civilians shout back.

T+ 03:42: Gunshots are heard from another compartment. A near panic ensues, with the ODSTs asking the sailors if they have seen any weapons on the civilians. The civilians in turn accuse the Navy of executing prisoners. Hernandez urgently, somewhat successfully, attempts to restore order by shouting that the sound is coming from shrapnel hits. Shrapnel can indeed be heard hitting the Feeling Lucky's hull, but while the sound fades as the cruiser turns to avoid the blast, the gunshots do not. Hernandez keys his radio and demands a situation report from the next bay over.

T+ 03:47: Civilians see dead bodies drifting in the vacuum outside, and a riot ensues. Hernandez and another ODST manage to fall back to the exit before the civilians overwhelm them, but the sailors and five other ODSTs are trapped in the hangar. Desperate to save his men, Hernandez keys the airlock controls, opening the hangar to vacuum.

Aftermath
The leaked record was never acknowledged by the UNSC. Records requests were rebuffed, though post-War leaks indicated that both Sergeant Hernandez and Lieutenant Chaisson filed complaints and demanded a complete investigation. Members of Chaisson's squad were transferred out of the ODSTs. Most were stationed on Reach, and are listed as MIA.

UNSC

 * Space
 * Charon-class light frigate UNSC Upon the Parapet - Stolen by the Outriders, later scuttled and destroyed.
 * UNSC Feeling Lucky


 * Personnel
 * Alfonzo Hernandez - Commander of the second boarding party
 * Angelica Chaisson - Commander of the ODST platoon that boarded the Upon the Parapet.
 * Georgy "Gui" Montag - One of the primary instigators of the massacre.

Outriders

 * Space
 * Charon-class light frigate UNSC Upon the Parapet - Scuttled.
 * Ledyanyye Bliki-class convoy escort Cheriton's Viper