In its second episode, Miss Fisher's Murder Mysteries randomly opens with a would-be Fagan, Mr. Merton (Jacek Koman), discovering one of his little girl pickpockets, Jane (Ruby Rees), is more violent with a fork than he anticipates. This seemingly disconnected scene quickly connects to this week's mystery, as Jane is next seen on a train platform, eyeing a seemingly unaware Miss Fisher, who is busy admiring the new Hispano-Suiza car she's on her way to pick up with Dot. But Fisher has eyes everywhere, not just for Jane, but the abusive mother, Matron Henderson (Abbe Holmes), berating her adult daughter Eunice (Maeve Dermody) behind them in line.
Robinson: Your shoe seems to have the ballistic capabilities of a .38 revolver.
Fisher: Fancy that!
After sending Bert and Cec back to her place to repay them for bringing the bags, Fisher starts making eyes at the young men on the platform, one of whom is far too taken with Eunice to notice. Back home, Bert and Cec are delighted to discover their payment is a brand new car. They're welcomed into their new jobs by the final piece of the cast, Mr. Butler (Richard Bligh), whose drink serving hides his Australian Imperial Force vet background. Back on the train, Dot witnesses a nasty spat between Matron Henderson and Alexander Cotton (Mike McLeish), whose son Eddie is running around. From Cotton's response to seeing her, they've have had ugly run-ins before.
But that's nothing on the overnight stop when the jerking of the train back into motion jars a scent down the car that catches Fisher's attention. The smell is chloroform, used on Eunice, who Fisher finds locked in, lying on the floor, her mother gone. She stops the train to alert the conductor, though any plans she has to work with the police are held up by Police Sergeant Brent (Brett Cousins), who has no idea who he's just met. At least Constable Collins (Hugo Johnstone-Burt) is here. Fisher corners Collins, and points out the train, which is an express, stopped during the night. Next thing you know, she's leading a party down the tracks to the water stop, where Henderson's body hangs from the tower.
Robinson arrives in time for Fisher to point out Henderson's jewelry is missing. When he starts questioning the passengers, Fisher contrives to have Cotton visit her and then offers her compartment for Robinson to interview him, so she can listen and suggest avenues of inquiry. Then she's off to question Eunice, learning Cotton blamed the Matron for his wife dying in childbirth after she had Eddie. But his being on the train seems to be a fluke; he's only on it because he won tickets to a seaside fair. Moreover, he's not a hardened man who could pull off such a last-minute plot; Fisher notes his hands are far too soft.
Robinson gives up keeping Fisher out, taking her to investigate the Hendersons' compartment. She was dragged out the window with no struggle from either her or Eunice. But before they can get much further, Jane shows up with all the old lady's jewelry, caught by the local police. Obviously, she didn't kill Henderson — the kid is barely twelve. But Jane does know something. Since she won't talk, Fisher announces her car has arrived, and she's leaving with the kid in tow, as well as Dot and Eunice.
By doing so, Fisher gets those lovely young men from the train platform to show up: the fiance, Alastair Herbert (David Berry), and her cousin, Lindsay Thompson (Dale March). Herbert is a medical student on scholarship, while Thompson is studying law and crime. Thompson claims to have liked his aunt, but she thought Herbert was common because his father was a button salesman in Ballarat. Herbert takes Eunice away in a hurry, raising Phryne's eyebrows. That evening, Miss Gay (Victoria Eagger) shows up, claiming to be Jane's aunt. Fisher is not fooled, especially when the girl goes into pure panic.
It's enough to get Jane to talk. She saw the murderer grab rope and found the jewels on the side of the tracks. She also saw either Herbert or Thompson stow away on the train too. Thompson, it turns out, is a degenerate gambler in debt, while Herbert has failed out of school. Robinson brings Herbert in for questioning, but he was picked up for soliciting a prostitute and spent the night in jail. And Matron Henderson left Thompson everything. But he claims a watertight alibi — he is the "Herbert" picked up for being at the bordello, using Eunice's fiance's name. He's been doing this regularly, so if he were arrested, he wouldn't be kicked out of school.
Cec, meanwhile, takes a room with Miss Gay and meets Merton, who was once a hypnotist. He attempts to question Ruth, Jane's BFF, but Merton catches him and hypnotizes him. Next thing you know, Ruth is there with Jane stealing everything from Fisher. But when Merton comes in thinking to hypnotize her, it turns out Fisher's not nearly as easy to get one over on as Cec. Merton is arrested. The next morning, Robinson stops by to say Merton and Gay are behind bars, and the police are finding the nearest relatives for all these girls -- except Jane, who Fisher decides to foster.
Fisher asks Robinson to stay, as Eunice has arrived for tea, and her handwriting is a match for the writing on Cotton's "free tickets." Eunice claims it was only supposed to be a jewel heist, but her mother woke up, so Herbert killed her. Fisher's not buying it. Herbert always planned to kill her. Discovering the money went to Thompson means he's just going to have to kill another one too. Thankfully, Fisher and Robinson get there in time to save Thompson from being murdered, but only just.
Even so, Robinson recognizes that without Fisher, the case never would have been solved. The episode ends with him stopping by for a drink and a thank you. It's the beginning of a beautiful partnership.