Shannon Terror — Theodora Dubois

When two American women, cruising in a small boat on the Shanon, are obliged to seek help at a nearby Irish castle in starting their cranky engine, they step squarely into the middle of a highly dangerous situation. After repeated knocking brings no response, they hear a faint cry for help within, push open the unlocked door, and find a dying man. And so, because he tells them who shot him and why, they become the object of a relentless effort by the murderers to silence them forever.

The motor on their launch had conked out and a flash storm had driven Constance Grant and Mattie Van Clief to look for shelter and aid at a remote Irish castle. Instead of help they found a semi-delirious man with a bullet wound in his chest. Before he died, he babbled of a frightful secret…

With this knowledge the two Americans were in a dangerous spot.