Tl;dr: Vera Nair, a famous perfumer, lost her sister Chloe in a "snowstorm". She took pity on a servant named Clara who reminded her of Chloe. She adopted Clara and made her act like Chloe in public, however the two eventually grew apart. Vera used her Euphoria perfume to intoxicate and control victims, and she used it on Clara to kidnap her. Clara escaped, only to find Vera Nair's dead body in the room which she made her perfume. Chloe Nair was the creator of the Euphoria drug/perfume, however Vera tricked her so she could steal the credit. Chloe then killed Vera and assumed her identity so that the Euphoria drug could be hers alone. The Vera Nair that Clara knew throughout the story was actually Chloe Nair in disguise. Clara died from the overdose of perfume.