In February 1887, Caitriona Wallace and Émile Nouguier meet in a hot air balloon, floating high above Paris. But back on firm ground, their vastly different social strata becomes clear. Cait is a widow, forced to chaperone two wealthy Scottish charges. Émile is expected to take on the bourgeois stability of his family's business and choose a suitable wife. As the Eiffel Tower rises, a marvel of steel and air and light, Cait and Émile must decide what their love is worth. Seamlessly weaving historical detail and vivid invention, Beatrice Colin evokes the revolutionary time in which Cait and Émile live – one of corsets and secret trysts, strict tradition and Impressionist experimentation.