With 48 minutes remaining before the train reaches the next station, Sherlock declares that William and he can find the murderer in time. Sherlock relies on the evidence at the scene, while William pursues a psychological profile of the killer.

When William James Moriarty claims responsibility for being the Lord of Crime in all the papers, aristocratic condemnation and public anger falls upon the Moriartys. The final problem of the Moriarty Plan that William has concocted at long last begins.