Clara, a botanist, points out a faint, unusual scent lingering in Alexander's study that resembles a rare, potent sedative, causing Evelyn to question the official time of death and making her realize the killer possessed specialized knowledge beyond a simple murder. Evelyn, testing a faint residue on Alexander's untouched teacup, notices it glows faintly under her UV light, a spectral, almost phosphorescent green, revealing a chemical signature far beyond simple tea.

The Alchemist's Brew