Read the "What's so special about this file?" question in the "About this UHS file" topic to learn how this hint file is arranged. The hints below will match the locations with the topics that you need to look under.
Sarah's Boyfriend: 221B Baker Street, Alley, Sarah Calloway's Flat, Chancery Opera House, Belle's Parfumerie, South Kensington Field, Southwark Morgue, Scotland Yard, Eaton Dormitory.