1860 ushers in the era of iron ships, Richard Sibley, a builder of wooden ships, stubbornly resists the change, which leads him to forbid the marriage of his daughter Rose to John Rhead, a proponent of the new method. This injustice outrages John's sister Gertrude so much that she breaks off her engagement to Sibley's son Sam. Meanwhile, John and Rose elope.

James Rallston, facing financial hardship, marries a wealthy invalid widow with a daughter, Jean, and plots to control her fortune. He orchestrates her confinement in a sanitarium by drugging her and falsely claiming she is insane, with the help of a conniving doctor and sanitarium keeper. Fifteen years later, Rallston has lost Jean's fortune through speculation and seeks help from John Bigelow to recover it, offering Jean as a reward. Bigelow, suspicious of Rallston, discovers the truth about the widow and Jean's father, and rescues the widow from the sanitarium.