A post-war salvager Rion Forge, captain of the Ace of Spades, discovers a link to the location of her father, who was lost on the UNSC Spirit of Fire in 2531. Using this information, she manages to locate a wartime wreck that she believes contains the secrets to the whereabouts of her father. During the mission to recover the information, her crew is confronted by Covenant remnant salvagers, and manage to recover a human imprisoned with them. Rion and the crew of the Ace successfully obtain the information, and use it to find the last known location of her father's ship, the UNSC Spirit of Fire at the Etran Harborage. Rion and her crew travel to the Forerunner shield world and get involved in a battle with the same Covenant remnant salvagers, ultimately escaping with a fragment of a Forerunner ancilla and the knowledge that her father's ship escaped the Etran Harborage, but without their slipspace drive.
Rion Forge and the Ace of Spades travel the galaxy in search of her father, stopping in Venezia along the way.