The Enigma Game by Elizabeth Wein

A German soldier risks his life to drop off the sought-after Enigma Machine to British Intelligence, hiding it in a pub in a small town in northeast Scotland, and unwittingly bringing together four very different people who decide to keep it to themselves. Louisa Adair, a young teen girl hired to look after the pub owner’s elderly, German-born aunt, Jane Warner, finds it but doesn’t report it. Flight Lieutenant Jamie Beaufort-Stuart intercepts a signal but can’t figure it out. Ellen McEwen, volunteer at the local airfield, acts as the go-between… Read more.