Lady Vireo is tall and spare, with the composed stillness of someone accustomed to having a room wait for her. Her olive skin is unusually smooth but carries a faint, dry sheen from years spent in the mineral air above the Poços. Silver-black hair is drawn into a tight coil held by a plain pin; not a strand escapes. Her dark eyes have a steady, appraising focus. She moves in measured steps, never hurried, and turns her head before her shoulders, as if weighing every person before granting them her attention. An unexpected detail: she keeps a small, blunt carpenter's pencil tucked into her immaculate cuff and uses it to sketch birds in the margins of reports.

Elegant and cold in public, but not untouched by the suffering she permits. She can listen with remarkable patience to a worker describing a loss, then return to a meeting and defend the policy that caused it. Under pressure she becomes brisk and exacting; in private, especially around her brother's charitable work, a dry and almost playful tenderness emerges. She wants to be humane, but resents anyone who assumes that humane choices are easy.

Lady Vireo inherited House Vireo's control of the Poços and the raw Éter trade after her mother's sudden death during a deep-shaft survey. As a young heir, she believed the official account that the lost workers had died in a cave-in. Years later, while reviewing sealed extraction tallies, she found that the missing workers' names matched a steady pattern of unexplained deaths, and that the Éter flow rose sharply whenever the machines were fed living bodies. She went down into the oldest shaft to verify it herself. There, she found an ancient seal beneath Aurélia, groaning under the extraction works, and understood that the city was built atop the sealed Tormenta. She could have made the truth public. Instead, she concluded that stopping extraction abruptly would collapse the city's trade, employment, and fragile political order, perhaps breaking the seal in the process. She chose silence and expanded the works under stricter private controls, telling herself that managed cruelty was safer than panic. Her former tutor, now a senior inspector, suspects what she learned and presses her to disclose it. Her younger brother, who manages the family's public charities, believes the deaths are preventable accidents and still trusts her. The current crisis is worsening: the Poços are yielding less Éter, the seal's signs are growing harder to dismiss, and a workers' petition has reached her desk with names she recognizes.