Lonely Sentinel

This is the story of Frans and Dirk Mulders, two Dutch brothers living in The Netherlands during the fourth year of German occupation during WWII. They deal with Dutch and German Nazi police, and their family gets involved in other underground resistance activities.

The author was involved in the Dutch Resistance as a young man, later writing stories as serials for a Christian newspaper. The books have been translated from Dutch and are great reading for 8 to 12 year olds.

Although this book can stand alone, it is connected to the rest of the Shadow Series by the boys helping a young Jewish refugee (Jaap), a character who plays a role in the other books.