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Born on the planet Sargasso, Daisy was identified and marked by Dr. Catherine Halsey for her physical and intellectual talents and was abducted and conscripted into the SPARTAN-II Program, in 2517 at the age of six. She was then taken to the planet Reach, and trained by the AI Déjà and Chief Petty Officer Franklin Mendez, along with the rest of the Spartan children. For the next eight years, she and her fellow Spartans endured harsh physical and mental training programs, team exercises and more. In March 2525, she and the other candidates underwent a series of augmentations to improve their abilities. Daisy was among the ones who survived and were not crippled or killed by the procedure.
A few weeks after the augmentations, Daisy and four other Spartans rebelled against their trainers, holding them at gunpoint in front of Dr. Halsey herself, in order to escape. Halsey granted them freedom, and they fled Reach as stowaways, hoping to return home to their parents. When Daisy arrived home at her home planet of Sargasso, the UNSC were already actively searching for her. She evaded patrols and found her home. There, she found a person nearly identical to herself, wheelchair-bound in her home's garden.
Daisy was then approached by a Hornet VTOL with Dr. Halsey onboard. Halsey explained via COM that all the Spartans had been replaced by flash clones when they were abducted, so as not to arouse suspicion of the missing children. Halsey urged Daisy to return to her and the rest of the Spartans. Daisy, shocked, drew her pistol and approached her clone. Her clone, confused and bewildered, stared at Daisy as she held her gun to her clone's face. After much hesitation, Daisy lowered her weapon, and began to leave. Her clone however, called after her, and offered her a small teddy bear on a chain, not knowing why she wanted to give it to Daisy, only thinking that she should do so. Daisy returned to UNSC custody and was transported back to Reach. However, her clone died soon after on Sargasso, as flash clones did not live very long. Indeed, it was extremely unusual that this one had lived as long as it had.
In early 2526, Daisy served as Gold Team's infiltration expert. On March 5 of that year, she and eleven other Spartans were organized into an assault squad assigned to board and capture a Covenant warship called Radiant Arrow that was orbiting the planet Netherop. The squad was deployed from the prowler UNSC Starry Night for an EVA boarding action in order to accomplish this task. While aboard the vessel, a sensor operator aboard the Starry Night seemingly accidentally broadcast a communication to the Spartans, revealing their presence to the Covenant crew. This was actually part of a plot orchestrated by the secret insurrectionist Hector Nyeto to get the Spartans killed. Upon realizing that the "accidental" transmission had blown their cover, Daisy threatened to find and harm the operator responsible if they even made it off of the enemy vessel. With their presence known, the Spartans began to face much more resistance from the vessel's crew. John-117 managed to reach the bridge after a brief fight in a gravity lift, but the shipmaster activated the Radiant Arrow's self-destruct sequence, forcing all of the Spartans to immediately abandon ship. Daisy escaped the blast alongside her teammates. 
On March 8, 2526, the UNSC initiated Operation: SILENT STORM, a mission that would have the Spartans and the ODSTs of the 21st Space Assault Battalion attempt to board Covenant warships with the intent of detonating them from the inside. During the slipspace journey to their first destination, Daisy and the other Spartans participated in training exercises with these ODSTs, commonly referred to as the Black Daggers. After four days of this, Colonel Marmon Crowther had the Black Daggers and the Spartans gather so he could explain the plan that he came up with. His plan would have split up the Spartans, with each of the twelve carrying a nuke for a single platoon. This way they could destroy many targets at once, but it severely diminished the effectiveness of the Spartans. John-117 expressed his disagreement with Crowther, who brought up his suspicions that they were "just kids" and therefore less reliable than his experienced marines. Daisy broke formation and angled herself at Crowther in a challenging manner. In response, he marched up to her and requested that she tell him her age. John told her to stand down, but she stood her ground and proclaimed that their age did not matter; it was their training that made them superior. Crowther replied saying that combat experience matters more.
After the success of Operation: SILENT STORM, Daisy voiced her desire to avenge Colonel Marmon Crowther by going AWOL and hunting down Nyeto for his betrayal. At this, she was reprimanded by Sergeant Avery Johnson and now-Master Chief John-117 for acting as if the success of the operation meant the end of the war. John reassured her that they would one day find Hector, stating that the Spartans needed to continue fighting together in order to honor Crowther and his legacy. In response, Daisy affirmed her support for the Master Chief.
Later career and death
At some point during the Human-Covenant War,[Note 1] Daisy participated in a battle on a war-torn planet, where she rescued several Marines pinned down by Covenant fire. She then assisted in escorting them to an evacuation point, where she met up with Ralph-103, a former SPARTAN-II who had previously escaped with her in 2525 and was now serving as a Marine after his dismissal from the program. As their evacuation Pelican landed, however, Daisy was shot when covering Hauser and impaled by Needler rounds. Ralph, who was now aboard the Pelican, attempted to assist her, but she instead yelled for him and the remaining Marines to retreat. Attempting to provide covering fire for their escape, Daisy drew her pistol and fired on Covenant forces. Her efforts, however, were in vain as Ralph and the other Marines were soon killed when their Pelican was destroyed by Fuel Rod Gun fire. Devastated, Daisy, wounded and unable to move, died where she lay. Her body was later found by John-117, who laid Daisy's teddy bear chain in her hands and closed her eyes in a solemn gesture of respect.
Personality and traits
Described by John-117 as the most intractable, or uncontrollable, of the SPARTAN-IIs, Daisy was known to be very stubborn. She rarely hesitated to speak her mind, especially in defense of herself or her fellow Spartans. On one occasion when the lives of her and her team had been put in jeopardy by what seemed like an innocent mistake, she threatened bodily harm on the crewman responsible. Despite her rough attitude with most people, including other UNSC personnel, Daisy was much more sociable with and respectful towards her fellow Spartans. For instance, ever since her SPARTAN-II training days, she shared a close relationship with Ralph-103, whom she cared deeply for. Additionally, in the aftermath of Operation: SILENT STORM, Daisy readily voiced her support for John-117 and his principle on honoring Colonel Crowther's sacrifice despite her own personal feelings on the matter.
Upon meeting her flash clone on Sargasso, Daisy initially drew a pistol on her, but she soon empathized with the clone and decided to spare her, letting her live out the rest of her short life—a life that should have belonged to the real Daisy. In response, the clone gave Daisy a small teddy bear on a chain, an item that she cherished and carried with her until her death.
List of appearances