"You got to be kidding. That's incredible."
"It's science. Use it well, and we shall find what we're looking for."
Reigel was a member of the Moebius Foundation some time before the Second Great War, and personally knew Crown Prince Valerian Mengsk. The eventual defection of the Moebius Foundation destroyed Reigel's career, and he felt he had nothing left but servitude to Valerian.
After Nova Terra broke out of a Defenders of Man base and regrouped with Valerian, Reigel was assigned to aid her. He used a device to send a pulse through the neural inhibitor she had in order to restore memories that the Defenders of Man had wiped from her. It was partially successful, as she remembered a destroyed and infested Tarsonis City. Nova and Reigel set out to investigate a Defenders of Man presence there.
Reigel adapted her jump jet technology to her Covert Ops Crew's factory units, impressing Nova. Their squad secured garrisons outside of the Defenders of Man facility as Nova infiltrated the base. Reigel guided her to a communications terminal, where she discovered the Defenders of Man knew she was in the base and was preparing to purge it. Nova moved in further, discovering a psi emitter in the base. After she moved into the command room, Nova relayed to Reigel that the Defenders of Man were using psi emitters to lure feral zerg to civilian worlds, and they were planning to attack Tyrador IX in order to discredit Valerian.
Nova and Reigel arrived on Tyrador IX, and Reigel noted the high casualties and overwhelmed Dominion personnel, as well as the Defenders of Man fleet arriving to aid civilians. Nova deployed to the surface to thin the zerg hatcheries around the city of Elsecaro while Reigel set up a base of operations. He noted a strange warp signature he thought was zerg reinforcements, however it ended up being the Tal'darim Death Fleet under First Ascendant Ji'nara. They deployed a mothership, and set up shield projectors to defend it. Reigel noted that though they would destroy the Defenders, civilians would be harmed in the process. Reigel also requested that, if time permitted, Nova clear out the last few zerg hatcheries to collect some samples as they possessed an interesting mutation. He also asked her to investigate an usual energy reading coming from an island near the Tal'darim. Nova was able to destroy the shield projectors and the mothership, allowing the Defenders to rally and defeat the last of the feral zerg. Though Nova was upset that the Defenders of Man would take credit for the defense, Reigel stated he would inform the Emperor of their actions.
Aboard the Griffin, Nova was met by Highlord Alarak. Nova raised her gun against him, but Reigel stopped her, stating he was a guest. The two made a bargain, as the Defenders of Man had attacked a remote Tal'darim outpost and then scurried away before the Death Fleet could retaliate, and he vowed retribution for it.. Alarak would guide Nova to a source of terrazine to restore her memories, and then Nova would guide Alarak to the Defenders of Man. She agreed, and he guided her to Jarban Minor.
On Jarban Minor, Reigel noted the extraction devices that gathered terrazine from the local Jarban gliders. Reigel also noted a cave system and science facility that may contain valuable Umojan technology. Reigel also noted the Tal'darim presence under Ji'nara, and speculated that Alarak deployed her to cull his forces of weakness. Nova was able to retrieve the terrazine and leave the planet.
On the Griffin, Reigel set up microdoses of terrazine in order to mitigate the side effects of the gas. She took a dose, and recovered a memory of being briefed on a mission to Antiga Prime. Nova and Reigel arrived there, and Reigel set up a base for her as she tried to recover her memories while fighting the feral zerg that had overrun the planet. Reigel noted that if the zerg structures in the area were destroyed it would limit what breeds the zerg could send against her. Reigel also noted a subway system that could be cleared to transport her forces around the city, as well as a plasma weapon being stored in the city docks. Nova recovered the mission files from her operation there, as well as memories of her time there and of the Defenders of Man leader, General Carolina Davis. Reigel and Nova took this information to Valerian.
After Valerian announced his plans to Davis to step down from the Dominion, Reigel played as intelligence for Nova while she attempted to infiltrate Davis's compound. He moved weapons caches into the base, allowing Nova to resupply if need be. He watched as Nova infiltrated through the sewer system, and noted a visor being tested inside the sewers. When Nova escaped the sewers and infiltrated the base, Reigel pointed out the location of the two security rooms that locked Davis's door. In addition, he discovered two experimental technologies within the base that Nova could capture. When Nova found her old comrades Pierce and Delta Emblock in holding pens, Reigel stated he would send a security team for them. Later, Nova fought her former squadmate Stone, and after incapacitating him Nova told Reigel to send a team for him.
Nova captured Davis and brought her before Valerian as he made his speech to the people of Vardona. However, the Tal'darim attacked the city, hoping to exact their revenge on Davis. Reigel helped coordinate the efforts of the Dominion and Defenders of Man lower ranking members as they defended the city, and asked Nova to defend a science facility in the center of the city on the verge of a breakthrough. The Dominion was able to successfully repel Alarak's fleets, but Reigel discovered Davis escaped aboard the Medusa.
Soon after, Valerian ordered Nova to capture Davis alive. Nova disagreed, but Reigel stated that they had their orders. Reigel traced Davis to the Cerros Shipyards, where she and her remaining loyalists established a base and activated the Xanthos, an experimental war machine that Reigel had knowledge of. She sought to use it to destroy the Gorgon-class battlecruisers docked in the shipyards. He gave Nova a plan of attack; though they could not destroy the Xanthos while it was activated, they could destroy its weapons, and it was vulerable while it was repaired. However, when Nova and Admiral Matt Horner assaulted the Xanthos, it revealed a transformation mode even Reigel had no knowledge of, which a large thermal laser. The machine was destroyed nonetheless, and Nova infiltrated the machine. However, much to Reigel's horror, Nova defied orders and killed Davis.
Reigel later found Nova hiding on the Griffin, where he opened up about his past in the Moebius Foundation, and how what they were doing what his only life now. He stated that he and the crew were loyal to her above all, and they would follow her wherever she went. Nova stated that the Dominion would always need protection, and they would do in their own way without Dominion command. With that Reigel, now a vigilante and a fugitive, walked to the bridge with Nova and activated the Griffin's warp.