When Sophie's grandfather accidentally leaves his wallet, house keys, and cellphone at the train station, Sophie and her neighbor Tariq decide to bike across town to catch him before his train departs.
Their "quick errand" turns into a whirlwind of missed buses, accidental detours through a film set, helping a lost tourist, and carrying a suspiciously heavy cake box for a very bossy stranger.
By the time they reach the station, they've run a mini-marathon, made three new friends, and learned more about their city than they ever did in school.