Wendy and Damien have recently moved from the city to the sleepy village of Culkin, where they hope to raise children. But after trying every which way known to science, the doctor confirms that they are unlikely to ever conceive. The couple are in despair until they happen upon Rosemary Reagan, a local witch, who recommends various bizarre devices that she guarantees will give them the child they crave. While Wendy is squatting on an exposed hillside, Damien must ""fertilise"" a mandrake root with his ""seed"".

When their wish comes true, they soon find it carries a heavy price, as their fantasy of a blissful parenthood turns into a nightmare.