When a patient arrives at the Holmes Clinic plagued by a mysterious neurological disorder, Watson and the fellows discover they were forced to eat their parents amid a childhood survival incident. Meanwhile, Adam is struggling with how his future will change as a father.
A year after the passing of his friend and partner Sherlock Holmes at the hands of Moriarty, Dr. John Watson resumes his medical career as the head of a clinic dedicated to treating rare disorders. However, he soon finds that his old life is not done with him yet.