A widow has kept a vigil on the Northern coast of Maine, keeping a lamp lit for her long lost husband, drowned at sea. A stranger comes to her, claiming to have been the sole survivor of a shipwreck. Has she caught a spy? Phoning to Dick Harding, Liza explains her suspicions.
Leaving Dick to interview the man on his own, he learns he really is a spy. What’s the nature of his secret project? The local men are challenged to take up the dangerous task of watching for enemy submarines off the coast. Will the rustic fishermen rise to the challenge? Nazi’s find they have their hands full when they capture a feisty, 70 year old sea captain.
An old time militia of minutemen is formed when the call is rung out at the church bell. The motley band of volunteers knows the sea and coast like the back of their hands, and are more than willing to respond to Dick’s guidance in defending their homeland. Can the citizen militia hope to capture the submarine?