Elyse, Saul, and Arturo continue their unrelenting quest for the Lunersee stamps. Clues arriving in cryptic envelopes have expanded their search interests to include other priceless artifacts stolen during WWII. The Amber Room, an invaluable treasure stolen from Russia by the Nazis, tops Elyse's list. After completing a philatelic cruise, the trio evades a deadly crash scenario initiated by a sinister driver on a European highway. Another attempt upon their lives occurs on the shores of Lake Lunersee. The adventures continue into an underground cavern where their survival is uncertain.