When a microbiology university researcher returns from an expedition to Siberia, she and her team members fall ill from a possible revived pathogen or "zombie virus". Meanwhile, Watson catches up with his friend Sherlock Holmes after finding out he is alive, and Ingrid unexpectedly finds herself on the team's floor.
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.