Shadow on the Mountain — Margi Preus

Nazi Germany has invaded Norway, and fourteen-year-old Espen and his friends are swept up in the resistance movement. Espen gets his start by delivering illegal newspapers, then graduates to the role of courier, and finally becomes a spy, dodging the Gestapo along the way. During five years under the Nazi regime, he gains -- and loses -- friends, falls in love, and makes one small mistake that threatens to catch up with him as he sets out to escape on skis over the mountains to Sweden.

This thrilling novel from Newbery Honor winner Margi Preus is based on the real-life adventures of a Norwegian spy during World War II.