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 (1916-1917).