Johnny Has Gone For a Soldier

Young men are being drafted, while young women volunteer to serve in auxilary positions, freeing "A Man to Fight."
Rhys Shay has his draft notice, and is preparing to report any day now. Lucy Goodheart, the young woman his brother rescued from a sex trafficker five years before, has learned the art of telegraphy from her foster father. Now that she is out of school, she joins the U.S. Navy in the only capacity available, as a Yeoman (F). Not only does being a Yeomanette enable her to make use of her telegraphy skills, it lets her feel closer to young Mr. Shay.

One of the first thing Lucy does is intercept communications from a German spy ring.