While out on a walk, Eleanor Trewynn, her niece Megan, and her neighbor Nick spot a young, half-drowned Indian man floating in the water. Delerious and concussed, he utters a cryptic message about his family being trapped in a cave and his mother dying. The young man, unconscious and unable to help, is whisked away to a hospital while a desperate effort is mounted find the missing family in time. The local police inspector presumes that they are refugees...

When spirited Eustacie stumbles into a band of smugglers, she is delighted to be having an adventure at last. Their leader, young heir Ludovic Lavenham, is in hiding, falsely accused of murder. Pursued by the law, Eustacie and Ludovic find refuge at an unassuming country inn. There, the resourceful Miss Sarah Thane and the clear-thinking Sir Tristram Shield gamely endeavor to prevent Ludovic's arrest and Eustacie's ruin as the four conspire to recover...