Operation: WHISTLE STOP

Operation: WHISTLE STOP was an operation on the surface of Ven III in the Ven system on May 8, 2558, conducted by the United Nations Space Command to recover a bioweapon from the hands of a Sangheili and numerous Kig-Yar pirates, slavers, and smugglers.

Prelude
On May 8, 2558, a United Nations Space Command spy drone was sent to investigate the barren surface of the unclaimed planet Ven III—located at the borders of the Joint Occupation Zone—after a group of Kig-Yar settled on the planet and were operating in an old Covenant research laboratory. While scouting out the planet, the drone discovered the diseased corpses of the Kig-Yar inside the laboratory and an unidentified Sangheili Storm that had left the laboratory holding a canister several hours earlier. Admiral Serin Osman, Commander-in-Chief of the Office of Naval Intelligence, was alerted of the discovery. The Kig-Yar were discovered to have been killed by an unknown biological agent they were manufacturing within the laboratory.

Admiral Osman contacted Captain Thomas Lasky aboard and briefed him on the situation, stating that the Sangheili may be an agent of Jul 'Mdama and may have double-crossed the Kig-Yar in the lab, or that they released the bioweapon on themselves by accident. Osman ordered Lasky to deal with the situation while exercising extreme caution before the Sangheili could use the bioweapon against humanity. Lasky hand-picked a team of two SPARTAN-IVs, Naiya Ray and Gabriel Thorne. Due to the nature of the mission, Lasky decided that he must use the smallest team possible out of risk of alerting the target Sangheili to the threat and losing him in Ven III's extensive tunnel systems. After being briefed, the two Spartans were sent to Ven III.

The mission
The two Spartans were deployed to Ven III's surface by a. As Ray and Thorne made their way on the planet's surface, they encountered a number of wandering Kig-Yar but no organized resistance. The two entered a narrow canyon where they lost communications with Infinity due to a nearby jamming field. As the Spartans proceeded further into the canyon, they were observed by the Sangheili, who had just destroyed the UNSC spy drone that was delivering the feed to Infinity. Infinity ' s shipboard artificial intelligence, Roland, immediately alerted Lasky to this as well as the communications blackout, suggesting for Infinity to change course toward Ven III to provide backup for the ground team. Having been ordered to avoid direct engagement, Lasky instead had Roland summon Commander Sarah Palmer. Meanwhile, Thorne and Ray observed a Covenant structure for some time before entering it. Once they were inside, the two SPARTAN-IVs were ambushed by the Sangheili and a contingent of Kig-Yar. As a skirmish ensured, the Spartans were able to defeat most of the Kig-Yar, catching them by surprise by rocketing out of the structure using their armor-integrated thrusters. However, the Sangheili attached a shock device onto Thorne's armor and activated it. The electronic shock knocked Thorne unconscious and the Sangheili captured him. Escaping on a with Thorne, Spartan Ray quickly followed.

Meanwhile, aboard Infinity, Captain Lasky proposed sending another two-man Spartan team to backup Thorne and Ray. However, Commander Palmer insisted on the deployment of an entire SPARTAN-IV fireteam. As Ray continued to chase after the Sangheili, they eventually moved out of the range of the communications jammer, allowing Ray to contact Infinity. Ray followed the Sangheili and Thorne into a deep subterranean tunnel where she discovered an enormous cavern filled with former Covenant vessels and vehicles; a major hideout for Kig-Yar pirates. Although the UNSC originally estimated there to only be around a hundred Kig-Yar on the planet, Ray realized that there was at least two hundred thousand of them. Noticing Kig-Yar smugglers, black market arms dealers, slavers, and pirates operating with in the cavern, she saw the Sangheili and a Kig-Yar carrying Thorne's unconscious body into a hangar bay. However, a Kig-Yar snuck up behind Ray and ambushed her. As her signal with Infinity terminated, Lasky ordered Roland to carry out the course change towards Ven III and to call for all teams on deck. Shortly afterward, Ray was able to kill her attacker and reestablished contact with Infinity.

Ray found a Spectre and proceeded into the pirates' base. Upon exiting slipspace, the Infinity was met by an advance fleet sent by the Kig-Yar pirate queen. They immediately retaliated launching multiple fighters to counter the pirate force in space. A rescue convoy was launched and managed to break through the fleet. They immediately entered Ven III's atmosphere and launched two HAVOK missiles into the base's entrance resulting in the destruction of the back-up fleet and the Kig-Yar pirate queen. Palmer and Majestic were deployed into the base and eliminated many of the pirates before proceeding to Ray and Thorne's location. Ray eventually found Thorne and attempted to hold the Sangheili agent in place till the rescue squad arrived but the Sangheili managed to escape. Ray relayed Thorne's location to Palmer before pursuing the agent. Ray then grabbed a Ghost and pursued the Elite, managing to disable his Ghost outside the base. Before Ray could take any further action against the Sangheili, a prowler landed nearby and several ONI agents told Ray to stand down. Ray was handed a report from Admiral Serin Osman with orders to detain the Sangheili and the bioweapon. The Sangheili was then led to the prowler. Thorne was rescued and returned to the Infinity.

Aftermath
Discussing the aftermath, Lasky told Palmer not to be angry at Ray for her actions due to the circumstances. He also told Palmer that his debriefing with Osman went surprising well despite the covert operation turning into a battle. Palmer asked if he learned anything about the captured Elite, but Lasky explained he was told to drop the subject. Lasky then told Palmer that he saw a memo sent by an ONI analyst to HIGHCOM concerning a growing number of Kig-Yar pirates setting up bases at trade routes and the possible outcomes for ignoring the threat. Lasky speculated that since the UNSC ignored ONI's demands for actions against the pirates, ONI staged the bioweapons accident in order to lure the Spartans to the planet, thereby forcing Infinity into a situation in which they would have to destroy the pirate base. He wondered which was worse: that ONI played them or that they fell for the staged act. Lasky then asked Palmer not to let him forget about what they learned that day.

List of appearances

 * Halo: Escalation
 * Halo 5: Guardians
 * Limited Edition dossiers