I Spy by Natalie Sumner Lincoln is a thrilling and suspenseful mystery novel that keeps readers guessing until the very end. The story follows a young woman named Maude Farris who finds herself embroiled in a dangerous game of espionage and intrigue. As Maude uncovers a web of lies and deceit, she must use her wit and cunning to outsmart her enemies and protect herself and those she loves.

Lincoln does a masterful job of building tension and suspense throughout the novel, keeping readers on the edge of their seats with each twist and turn. The characters are well-developed and engaging, and the plot is full of unexpected surprises that will keep readers guessing until the very last page.

Overall, I Spy is a captivating and enthralling read that will appeal to fans of mystery and suspense. Lincoln's expert storytelling and attention to detail make this novel a must-read for anyone looking for a thrilling and entertaining read.

Book Description:
Here is a novel whose pregnant caption suits these parlous times. . . . It's all about a German spy plot to steal two American inventions deemed of inestimable value for war use. One is a camera for taking a map of the country from an airship. The other is a process for making glass armor—coats of mail of interwoven mica and glass that Mauser bullets cannot penetrate. Washington, D. C., is the locale. . . . Almost everybody turns out to be a bit of a spy, and the last unraveling chapter certainly carries the element of complete surprise - Summary by Book Review Digest, v.12 .