Evelyn realizes the strange sedative scent in Alexander's study and the plant toxin that killed Clara were both derived from the flora in the subterranean greenhouse, confirming the killer has intimate knowledge of Alexander's secret lab and access to his most dangerous creations, making the investigation feel impossibly complex. As Evelyn collects samples from the vials, she notices a faint, metallic sheen on the underside of her own labeled vial, and with a horrifying realization, sees a tiny, almost invisible syringe needle embedded in its base, implying the contents were not just meant to be observed, but administered.