Greek fire
Anxious to save Kristina, Sinbad reveals to the Khalif that Simon possesses the formula for an explosive called "Greek fire" and will share it with the Khalif in exchange for Simon's, Kristina's, Omar's and his freedom. The Khalif refuses to release Sinbad and Omar, but while they are incarcerated in the dungeon, Simon and Kristina give the ruler a private demonstration of Greek fire.