Thief of Baghdad

From the back cover:

THE QUEST FOR THE BLUE ROSE

And it was declared throughout the kingdom that whosoever passed through the trials of The Seven Gates and returned triumphant with a lone, blue rose would be hailed Sultan of all Baghdad and would receive in marriage the hand of fair Princess Amina.

Unthinkable that a thief, the lowliest of men, should offer his sword and his life on this perilous crusade. A crusade blocked at every turn by dangers of raging flames, invisible beasts and hooded faceless men.

Unthinkable that even the bravest would survive to tell the thrilling tale -- and yet, one man did!