When twelve-year-old Sam Hobbs finds a mysterious magnifying glass buried in the barn on his grandfather's farm, he quickly learns that it has extraordinary powers. The magnifying glass transports him back in time to 1860 and the Blue Heron Inn. But this is no ordinary inn, and this is no ordinary day. Sam soon finds himself in danger, and he must think quickly to stop a murderer and find his way home under the path of a great blue heron.