"The Unseen Ear" is a mystery novel by Natalie Sumner Lincoln, originally published in 1920. The story follows private detective Lucille Daviot as she investigates a series of burglaries, but soon discovers a more sinister plot involving murder, blackmail, and secret codes. With the help of her friend, reporter Don Wilson, Daviot navigates a web of clues and suspects to solve the case. This fast-paced and thrilling mystery novel showcases Lincoln's talent for crafting intricate plots and engaging characters.