After returning to Venezia from the debris of Etran Harborage with the fragment of a Forerunner AI known as Little Bit (Halo: Smoke and Shadow), Rion Forge and her ship, the Ace of Spades, spent several weeks on the colony world getting their ship repaired, rooting out ONI spy Kip Silas, and mourning the loss of crew-member Cade McDonough. When they discovered Gek ‘Lhar, Sangheili Lieutenant under Jul ‘Mdama and Cade’s murderer, was going to be at an auction nearby, the team devised a plan to ambush him as retribution. The plan fell apart when ONI agents intercepted Rion and the Ace of Spades crew during the auction, taking them into custody for acquiring Little Bit.
ONI confiscated Little Bit, along with all of the Ace of Spades’ salvage from their trip to the Etran Harborage and every warehouse the crew had including person items, and left the crew with just their ship. Infuriated at their situation, Rion and her crew plotted revenge on ONI by travelling to Geranos-a, the location of the wrecked UNSC Rubicon, which crashed there in 2554, but was only discovered by ONI immediately prior to their abduction of the Ace of Spades crew. At the wreckage, the Ace of Spades found that the crew was killed, but 343 Guilty Spark, who hijacked the Rubicon and initiated the voyage, was still alive.
Spark, having unlocked his prior memories as Chakas before becoming a monitor, convinced the crew to assist him in his journey to find the Librarian, and set off on their journey. Their trip eventually took them to Earth, where the crew trekked to Mount Kilimanjaro and uncovered a hidden Forerunner facility that contained an imprint of the Librarian. Here, Spark abandoned the crew and attempted to access the Domain, though he was denied. Spark instead decided to return to the Ace of Spades and offered his services to Rion and the crew.
Renegades continues the story of Rion Forge’s search for her father and 343 Guilty Spark’s search for the Librarian.
The Ace of Spades travels to several locations in Renegades, notably returning to Venezia, the Etran Harborage, and ending in Africa on Earth.