This thrilling psychological science fiction starts with a mysterious brain-swapping experiment performed by a neuroscientist on two identical twin sisters. The twins have the same physical attributes, including fingerprints and irises, making it impossible to tell them apart. The scientist is dating one of the twins while married to the other. His research uncovers a confounding mystery, but then tragedy strikes when one of the twins is found dead. With the stakes as high as ever, the scientist must uncover the truth before it's too late.