In Episode 3 of The Mystery of a Hansom Cab, titled "In the Queen's Name", the narrative intensifies as Detective Samuel Gorby zeroes in on Brian Fitzgerald, the affluent wool merchant and suitor to Madge Frettlby, as the prime suspect in Oliver Whyte's murder. Gorby's investigation leads him to uncover compelling evidence: Fitzgerald was the last person seen with Whyte, assisting the inebriated man into the hansom cab on the night of the murder. This discovery prompts Gorby to take decisive action, resulting in Fitzgerald's arrest and formal charge for the crime.