Thea's first hours on the battlefield are a crucible of terror and discovery. She spots enemy scouts and feels a strange, instinctual block preventing her from taking the shot—a block that saves her life when the snipers who do fire are instantly obliterated by a mysterious, sky-borne explosion. Connecting the dots, she reports her theory to command: the scouts are bait, and the explosions are retaliatory GOG shells fired from an enemy hill. Her quick thinking and Priority Request lead to a successful countermeasure, saving countless UHF lives. This is her first major contribution, earning her the grudging respect of Squad Leader Kellerman and the attention of Captain Greysmith. She learns that the "shadow" she glimpsed was the shell itself, moving at impossible speed. The victory is pyrrhic, however; the Stellar Republic's possession of such advanced technology signals a terrifying new phase in the war.

The Stellar Republic launches a massive, attrition-based assault, flooding the trenches with thousands of identical soldiers. Thea realizes the horrifying truth: the enemy can duplicate themselves, and only killing the original body stops the copies. Her strange "gut feeling" returns, guiding her to identify the originals with supernatural precision. She begins a relentless, one-sided slaughter, thinning the enemy's ranks faster than any other marine on the line. This draws the attention of the manic, god-like Lieutenant Frost, who protects Thea as she continues her grim work. The constant use of this ability, however, pushes Thea to her physical and mental limit, causing a catastrophic Focus Overdraw that nearly kills her. She collapses, having carved a hole in the enemy's assault but also having shattered her own mind in the process.

After recovering, Thea is thrust back into the chaos. The Stellar Republic deploys a massive, armoured Captain who duels Lieutenant Frost in a display of physics-defying power. The Lieutenant wins, but the Captain's body is a suicide bomb, detonating in a blast that vaporizes two trench lines and mortally wounds Thea. While being treated, a crippling vision floods her mind: the western valley, which she had used as a landmark, has been subtly shifting. The rocks have moved. She realizes the Stellar Republic has been using illusion-tech to hide an entire flanking army, slowly creeping up the hill for hours. She drags her broken body and a bleeding medic to the edge, confirms the illusion, and sends a desperate Priority Request to Captain Sable. The retreat is sounded, saving thousands of marines from encirclement. Thea finally succumbs to her injuries as the UHF reinforcements arrive, completing the mission.

Thea awakens in a void and is integrated into the Allbright System, gaining a Faction-Trait (Soul Transfer), two Silver Abilities (Sensory Overdrive and Meditation Focus), and a profile of Attributes. She learns that the System is a reality-altering entity, that her past experiences with the UHF were all part of a grand recruitment and integration process, and that she has been marked as exceptional. She is assigned to Alpha Squad, the elite of her recruitment drive, and meets its members: the leaderly Corvus, the stoic Isabella, the friendly Lucas, the quiet Desmond, and the energetic Karania. Her joy is immediately shattered by Desmond's virulent hatred of Cyans and Isabella's cold distrust, based on the unsettling feeling her eyes cause. The squad is fractured before it has even begun. Thea's only solace is Karania's fierce defense of her and the promise of the System's power, but the social battle ahead feels even more daunting than the one she just survived.