When scientist Rachel Herz decided to study the connection between smell and memory, she chose five products emblematic of childhood: Coppertone suntan lotion, Crayola crayons, Play-Doh, Johnson & Johnson baby powder and Vicks Vaporub.

She studies the science of what’s called the Proustian phenomenon. The French novelist Marcel Proust writes about dipping a madeleine cookie into a cup of linden tea and the aroma immediately bringing him back to a long-lost memory.

Producer Julia Longoria has always had that relationship with Vicks Vaporub — the scent transports her right back to childhood, to days in bed with the flu at her grandmother’s house in South Florida. Julia and her cousins all knew not to tell grandma when they were sick, or they’d risk being slathered with "Vickicito".

Julia never had a reason to wonder why grandma loved Vicks so much, but this week’s episode reveals grandma’s love for the product is deeper than Julia imagined. And while investigating grandma’s (and the world’s) Vicks obsession, Julia is pulled into her family’s past, back to Cuba, before the Revolution.