Sirens and Spies — Janet Taylor Lisle

The Past Has its Secrets Mary and her sister Elsie's violin teacher, the flamboyant Miss Fitch, lies in the hospital, recovering from a brutal attack. Elsie, Miss Fitch's favored, talented student, refuses to visit her, declaring her a fraud, and worse. What has turned Elsie against her formerly beloved teacher? Mary can't believe the shocking secret from Miss Fitch's past that her sister has unearthed. She insists that they confront the teacher to get to the truth. But the sisters discover that truth — about the grim days in occupied France during World War II, about the mysterious incident that put Miss Fitch in the hospital, and even about themselves — is not that simple.