The Crimson Stain: Under the Moon’s Shadow (Omegavers) #English versions

One room. One body. One secret that binds them in blood.
Aira is a ghost. A hidden Omega working as a night-shift janitor at the prestigious Obsidian Throne hotel, she has spent years scrubbing away the stains of the elite while hiding her own scent. But her invisibility is shattered in Suite 999, when a high-profile politician dies in her arms during a fatal twist of fate.