In 1886, orphaned Irish siblings Mary and Tom arrive in New York City via ocean liner, and quickly find themselves on a wild, cross-country journey aboard a transcontinental 'Orphan Train', where they meet an extraordinary new friend who will change their lives forever.

Aisha, a 13-year-old girl, lives in 11th century Al-Andalus, where fireworks displays are the most popular entertainment and the one big passion of young Aisha, who dreams of becoming a professional rocketeer one day. Someday, the adventurous alchemist Txawir comes to town, using Aisha for his own purposes and convincing her to steal a banned book from the Calipha’s library without permission. Txawir disappears with the book, for which Aisha’s father is blamed. To recover the book and save her father, Aisha embarks on an adventurous journey…