When mechanic Jeff Obold meets the wealthy and mysterious Bruno Rubin, he is exposed for the first time to the finer things in life. But Jeff soon discovers the source of Rubin's power: a caged creature called a "Darkling," which possesses the power to create incredible wealth for the person who will pledge unending "companionship." Now, as Jeff sinks further and further into the blackness of a soul sold to the devil, he will discover there is a high price to pay for the fulfillment of his dreams.

Sarah LaMere had loved Michael Rome Matthews for a long time. She witnessed him marry her best friend, only to lose her along with two sons in an accident. Now that they are together at last she is devastated to learn that she can never have children. While Rome tries to accept this, Sarah believes motherhood is her only path to happiness and security with the man she loves and she becomes increasingly unbalanced. Seemingly out of nowhere children's clothes and toys appear in the house and then a strange young girl named Melissa appears, whom Sarah treats as her own child. When their landlady is horribly murdered after questioning Melissa, Rome fears the line separating reality and fantasy has been crossed.