The Cullen females become pregnant under the 'Ubertas Luna" (The Fertile Moon): a rare event that only occurs when a vampire with fertility powers is born under a crescent moon, the same shape a vampire bite leaves on its victim. There is no precedence for such a birth, or child. How will the Cullens escape the scrutiny of the Volturi - and will they survive this unprecedented wholly vampiric gestation?

Bella was not Edward's mate at all. But Carlisle's. Alice knows this. Since before Bella was born.