It has been eight years since Dicey Tillerman brought her brothers and sister to Crisfield, Maryland to live with Gram after their mother abandoned them at a shopping mall in Connecticut. Dicey is now twenty-one and, with characteristic single-mindedness, has dropped out of college to pursue her dream of becoming a crafter of fine sailboats. Confident that self-reliance and hard work will be enough to carry her through, Dicey forges ahead, intent on starting her own business. Her confidence arises from prior successes in overcoming challenges far beyond the experience of most young adults of her age. Her friend, Jeff Greene, wants to marry her, but Dicey has a plan: "first the boats and then marrying Jeff."

Dicey, determined to succeed on her own, focuses all her time and energy on her work, but because of her stubborn insistence on doing things her own way, the business does not go well, and in the process she neglects those whom she cares about most in her life, and almost loses Jeff, the one she loves. Dicey is robbed by a seemingly kind drifter whom she hires to help fill her orders, and her venture ultimately fails. In its dissolution, however, she learns important lessons about business and about relationships. Through her mistakes, Dicey discovers the need for humility and the importance of being open to the counsel of those more knowledgeable. She also learns to accept help when it is needed and to discern between those who care about and those who would take advantage of her. Most significant of all, Dicey realizes that one has to "work as hard at people as at anything else."

Published in 1989, Seventeen Against the Dealer provides the conclusion to author Cynthia Voigt's seven-volume Tillerman saga. Dicey's brothers and sister, introduced in the first book, Homecoming, are almost grown. James, intelligent and brooding, is at Yale, trying to win a scholarship to enter the pre-med program, and Sammy, practical and capable as ever, is in high school and showing a great aptitude in sports. Maybeth, always shy and slow to grasp her schoolwork, still struggles academically, but has discovered an amazing capacity to care for people. The fear that used to be in her eyes has been replaced by a serenity that comes from knowing that she will always have the support of her brothers and sister, and a home with Gram. Gram herself is characteristically outspoken and cantankerous, but, having dared to let the Tillerman children into her life, her house is now filled with happiness, music, and love.

Like the other books in the series, Seventeen Against the Dealer is notable for its depth of character development and its sensitive exploration of the ties that bind families together. Dicey comes to understand that there are no guarantees in life, and that while the attributes of tenacity and the willingness to work are vital to achieving success, they amount to nothing without the love and mutual support of others. Because Dicey is open to learning and growing, her future looks bright, and the reader gets a clear sense that she will approach it with dignity, confidence, and gratitude for the opportunities that come her way.