Ariel, Miranda's clone, is becoming a person in her own right. Ariel is living with Miranda and they arebecoming close, as sisters do. Everything seems perfect, until Miranda starts noticing things that don't seem to fit with the Ariel she knows. She sees her sister in places she shouldn't be, doing things Ariel would never be doing, and Miranda begins to wonder if she herself is going crazy. But then Ariel beginsacting stranger than ever and Miranda gets a horrible feeling... what if there's more than one clone? And if so, can she find out what's going on and give Ariel back the life she's built before it's too late?