After the Nazi occupation of her hometown Amsterdam, Hanneke spends her time finding and delivering black market goods to customers. She looks out for herself and her family, trying to forget her pain over her boyfriend who was killed on the Dutch frontlines. When a client asks Hanneke for help, her first reaction is to stay away from trouble. Mrs. Janssen has been hiding a Jewish girl and that girl has vanished. She asks Hanneke to use her skills in finding things to locate the missing Mirjam.
As Hanneke searches for Mirjam, the mystery of her disappearance becomes more complicated. Hanneke also finds herself drawn into the resistance movement and more danger than she expected. Girl in the Blue Coat deals with both the trials of World War II life as well as the nobility of the people who resisted Nazi control. The mystery aspect draws attention away from the darkness of an awful time and keeps the story appropriate for teen readers. I recommend this read for teens both for the fast-paced story and the interesting historical elements.