Superstar genetic engineers Clive (Adrien Brody) and Elsa (Sarah Polley) specialize in splicing together DNA from different animals to create incredible new hybrids. Now they want to use human DNA in a hybrid that could revolutionize science and medicine. But when the pharmaceutical company that funds their research forbids it, Clive and Elsa secretly conduct their own experiments.

The result is Dren, an amazing, strangely beautiful creature that exhibits uncommon intelligence and an array of unexpected physical developments. And though, at first, Dren exceeds their wildest dreams, she begins to grow and learn at an accelerated rate——and threatens to become their worst nightmare.