From Halopedia, the Halo wiki
In March 2553, she "welcomed" the captured Jul 'Mdama to the facility. She had the Sangheili placed in captivity, intending to learn more about Sangheili biology in order to manufacture bioweapons, making their own food indigestible to them with the ultimate goal of eventually targeting the entire species and starving them out.
She later visited Jul in his cell, accompanied by an armed guard. When Jul asked her why the sky was blue, she explained Rayleigh scattering to him. She informed him of the Jiralhanae uprising on Sanghelios and matters involving Avu Med 'Telcam and the Servants of the Abiding Truth's clandestine arms dealings. She made no effort to hide ONI's intentions of crippling the Sangheili, and even taunted Jul that his species would never be able to threaten Humanity again. When Jul complained about the food, he asked her to get him irukan, the Kig-Yar name for a Sangheili grain that the Kig-Yar grew. She noted that his children would miss him; he corrected her by informing her that Sangheili did not know their fathers. She countered that while the children didn't know their father, the father must know children; if the bloodlines weren't managed, they would be inbred. As she left she told Jul that he could be useful to her by just being himself.
Magnusson gradually began to let 'Mdama on walks outside his cell, albeit accompanied by the Huragok known as Prone to Drift and fitted with an explosive harness. Jul, having planned to escape the entire time, eventually coerced the Huragok into removing the harness, allowing him to escape via a portal hidden in a Forerunner structure. After learning of Jul's escape, Magnusson informed Admiral Parangosky, who quickly decided to remove Magnusson from her post as director of Trevelyan due to the doctor's incompetence. Parangosky arrived on Trevelyan and personally relieved Magnusson of duty. She promoted Hugo Barton in her place and had Magnusson detained at the Midnight Facility.
List of appearances