Amara (Yvette Duguay) and Ali (Scotty Beckett) exchange blood as children, to symbolize their love. They are separated, and Alis' father, Caliph of Baghdad, is murdered. Ali gets away, finds the Forty Thieves' lair, and falls asleep. He is discovered, but allowed to live. Ten years go by. Ali (Hall) finds Amara (Montez) bathing. The delirious plot goes from there, making brief stops in the land of operetta and mis-choreographed musical numbers.
The person in charge of Technicolor went wild in this film. The characters' clothes are color coordinated with their surroundings (the escaped prince is wearing pink and white--the boulders surrounding him are white and pink, etc). There is one main castle--it changes color depending on whether it's day or night, and according to what colors Montez is wearing. The insides of the castle change color from shot to shot, from green to beige to pink. William Fritzsche, Universal's Associate Technicolor consultant, created a dream world where the sky can be green (literally) and anything can happen.
The actors' looks are more important than their performances. Jon Hall is predictably heroic and dim. Maria Montez is drop dead gorgeous; her accent is thicker than usual, and she rolls her r's for some reason, making it hard to guess what some of her lines are. Turhan Bey is good in a bad guy/good guy role. Andy Devine has a relatively small role, so he doesn't do much damage.
This blissfully silly romp is worth seeking out.