The protagonist is a young British butterfly collector who, working for the British Museum in London, collected the little-known butterflies and moths at the time in Texas in 1840. The collector teamed with a Spanish senorita to collect them across Texas when traveling in an ox-drawn covered wagon over rough and muddy roads and through the ranges of hostile Native Americans. The book is about their collections and, at times, hazardous adventures. The text is a natural history of the butterfly and moth species pictured. The book is also a history of pioneer Texas of the 1840s as well as the ethnology of Comanche Indians.