Glasgow socialite Madeleine Smith laced her lover's cocoa with arsenic, resulting in the death of Pierre Emile L'Angelier. Emile's death put in motion one of the most famous murder trials to have ever taken place in Scotland, with an incredible twist in the tale. To this day, the case continues to fascinate. Dark Curiosities is a series exploring solved and unsolved crimes, mysterious happenings and truly nightmarish events.