Sleator's novels frequently draw on interesting social issues to create a suspenseful story. In this case, the novel's premise is that toxic chemicals could alter humans in potentially dangerous ways, although Jared, his grandmother, Annelise, and Lindie fortunately feel few negative effects.

Of greater concern is Sleator's suggestion that humans are frequently petty and selfish. While Annelise is a real sociopath, most of her other relatives also have few real redeeming qualities. Even the novel's hero and heroine, Jared and Lindie, are ruled by their passions. Jared has nothing on his mind but being alone with Annelise, a possibly controversial plot element since she is his cousin; Lindie has cheated in order to achieve recognition by being admitted to an Ivy League school. Their grandmother is, evidently, also a thief, blackmailer, and self-imposed judge of others.