In 1897,
Sherlock Holmes receives a letter from his brother Mycroft asking him and
Dr. Watson to investigate a singer performing at a birthday party held by construction baron Sir Melvyn Bromsby for his daughter Lavinia. During the party, Bromsby is shot dead by an unknown assassin. Working with
Scotland Yard Inspector Lestrade, Holmes and Watson identify two suspects. One is Lavinia, who has a strained relationship with her father. The other is Grimble, Bromsby's partner, who he apparently caught embezzling. During the investigation, three more corpses are found which are connected. The first is Roy Hunter, a bartender at the party. The second is Horace Fowlett, Bromsby's lawyer. The third is an unknown man, later identified as Bromsby's troubled nephew, Wyatt Collins. Holmes also connects the case to the disappearance of Veronica Davenport and Jeffries, actors who co-owned a
theatre troupe Bromsby bought. Due to their being lovers despite Veronica also being in a relationship with the third owner, Richards, he was suspected, but ultimately let go. Eventually, Holmes deduces the culprits to be Lt. Herrington, a soldier in a relationship with Lavinia, his
manservant Spencer, and Collins. Spencer is actually Jeffries, who killed Davenport in a jealous rage and convinced Herrington to help him disappear. The two worked with Collins to take Bromsby's fortune. At the party, Jeffries disguised himself as Herrington, allowing the real Herrington to shoot Bromsby. Hunter was killed for recognizing the fake Herrington. Collins tried to steal Bromsby's will and killed Fowlett when he couldn't find it. When Herrington became engaged to Lavinia, Collins was no longer needed and killed. Grimble meanwhile had
embezzled to help families of workers Bromsby had wronged, which Bromsby approved of. Holmes tricks Herrington into confessing by falsely claiming Scotland Yard will find evidence of the murders and they're arrested. Holmes and Watson then prepare to investigate the singer as Mycroft requested. ==Development==