In real life, 221B Baker Street is the home of a bank. When fans send letters to Sherlock Holmes, bank employee Addy Zhuang, known as "e;Sherlock's Secretary,"e; replies. One day, the bank is robbed, but the thieves only take three letters addressed to Sherlock Holmes. The police conclude it was all a harmless prank, but Addy suspects something more malicious is happening. With the help of a true crime reporter, Addy and his friends launch their own investigation, which leads to murder and a decades-old cover-up connected to the BBC's "e;Great Erasure."e; Can Addy uncover the truth before more people die?