Grey

Doctor Elizabeth Grey is Requiem’s Head of Unnatural Sciences and its warmest presence: the British polymath who built the robot Klaus, covered for off-book operations she believed in, and grew close enough to Samantha Maxis that the story treats their bond as its quiet love story. Amy Louise Pemberton voiced her through the Cold War era; Abigail Marlowe carries her through Black Ops 6.

From handler to fighter

Five years of Terminus imprisonment — with combat training from Carver between torture sessions — turn the scientist into a soldier. Freed in 1991, she works the crew’s mysteries from Citadelle’s alchemy to the Nexus’s constellations, and at Janus Towers makes the arc’s most personal discovery: Requiem DNA samples including Maxis’s forcibly harvested eggs. She keeps what she needs and destroys the rest.

Ava

What she keeps becomes Ava — born 1993, conceived from Maxis’s eggs with Grey as surrogate mother — the child whose recorded message and hidden parentage anchor MWZ’s story decades later. Grey’s own road ends at Zaravan with the other Requiem leads; her daughter’s is still being written.