Keegan James and the Dragon's Heart Amulet
Peter Leslie

Keegan has been abducted, he just doesn't know it yet. His sister Terri, with the aid of renegade nuns, is sent to rescue him. And in the slave mines of Kilamanjaro, they meet Tosh, a one hundred and fifty year old teenager. Their quest to escape leads them in search of the Dragon's Heart Amulet. But they are not the only ones searching for this treasure...