Final answer:
In 'Illuminae', Ezra is a member of a flight group called Byron. This group is part of the military on the spacecraft carrier Alexander, which features prominently in the evacuation and conflict narrative of the book.
Step-by-step explanation:
In the book Illuminae by Amie Kaufman and Jay Kristoff, the character Ezra belongs to Flight Group known as Byron.
This is a group within the military contingent aboard the spacecraft carrier Alexander, which is part of the fleet evacuating the survivors from an attack on the Kerenza IV colony.
Through the narrative, we follow Ezra's experiences and communications as he is thrust into conflicts both external and interpersonal, showcasing his development as a pilot and character within the plot's futuristic wartime setting.