What would the police department look like if Sherlock hadn't returned 2 years after his "death"? New officer Matt is about to find out: between meeting Lestrade and Molly and solving a first case, he learns what it means when a police department makes a fatal mistake. Molly, though, knows that Sherlock is still alive and the big question is then: if Sherlock hasn't returned to London - where is he now?