Hunt for the Devil's Dragon, Paperback/Marianne Hering

If you're brave, follow cousins Beth and Patrick to Libya in the 13th century. The town of Silene is being terrorized by a vicious animal that is eating livestock. The townspeople believe it's a dragon sent by the devil. In order to appease the beast, the people believe they must offer a human sacrifice--a young girl named Sabra. When Beth tries to help Sabra escape, she too is tied up as an offering for the dragon. Meanwhile, Patrick and a new friend named Hazi join Georgius, a Roman knight who is serving in Africa to keep peace. Georgius decides to find the dragon and kill it. Georgius's plans go awry when Beth and Sabra beg him not to kill the dragon. The girls know the true secret of Silene--the dragon isn't its worst enemy.