In the mid-19th century, the Ammidon and Dunsack families of Salem, Massachusetts, have experienced very different fortunes in the merchant sailing trade to the Far East. The successful Ammidons revel in the captaincy of their adventurous and restless son, Gerrit. The Dunsacks' future rests on the shoulders of the opium-addicted and vindictive son Edward. But as Gerrit returns from a voyage to China, he brings with him something that will shake the staid society of Salem and his family's position in it, something far more potent than Edward Dunsack's opium.