- Author: Eric P. Kelly
- Read Aloud Grade Range: 5 - Adult
- Read Alone Grade Range: 7 - Adult
- Newbery Award
- Binding: pb
- Pages: 224
Joseph Charnetski is under oath to protect the Great Tarnor Crystal. The Tartars try to steal it and Joseph and his family seek refuge in medieval Krakow. An exciting adventure set in the late Middle Ages.