The U.S.S. Enterprise accidentally discovers Aldea, a planet with advanced technology that provides every need or want a person could have. Although Aldea has hidden itself from the universe behind a sophisticated shield, it's soon apparent that the discovery was no accident. Having lost the ability to reproduce, the Aldeans kidnap several children from the U.S.S. Enterprise, including Wesley, to perpetuate their race. When hostage negotiations fail, Picard struggles to find a method of penetrating the planet's shield while Dr. Crusher studies the cause of the Aldean sterility problem. Meanwhile, Wesley uncovers the key to the planet's sophistication-a computer known as the Custodian, whose power source is unknown even to the Aldeans.
