The second season of Miss Fisher's Murder Mysteries begins with multiple bodies in a locked room, discovered by the housekeeper, Mrs. Blunt (Jan Friedl) when she returns from her evening off at the pictures.
It interrupts Phryne's evening of flamenco lessons with Carlos (Fabio Robles) and drinking with Dr. Mac. Oddly though, it comes via Dot's sister, Nell (Anna Bamford), who goes by Lola and is entirely too made up and bottle blonde for someone from the catholic Williams family. Lola declares a dirty rotten copper has murdered her friend, an automatic ticket to the Fisher parlor.
Miss Fisher: We want them looking at the feathers.
The murder also derails Jack's evening, as his ex-wife, Rosie (Dee Smart), arrives at the station. Her father, George Sanderson (Neil Melville), the Deputy Commissioner, was one of the two bodies (lucky for him, not the dead one). It's not Jack's case, but he takes over immediately, telling Sgt. Crossley (Stephen Carracher) to take it up with the City Chief Commissioner Hall. He arrives at the same time Phryne does, to investigate on behalf of the victim. The dead girl is Lola's friend Lavinia, real name Sarah Holloway, and a "hostess" at the Imperial Club.
Jack weathers the inevitable introduction of his ex-wife and Miss Fisher reasonably well. He even manages meeting Rosie's new beau, her cousin Sidney Fletcher (Daniel Frederiksen). But he doesn't accept the idea his ex-father-in-law might have stranged the girl, deliberately or by accident, or that the poison he ingested was a suicide attempt after killing her. But the facts look damning. The door was bolted the door from the inside, and Sanderson is little help. He says he poured himself a drink, then remembers nothing, and swears he's never seen the girl. As he ordered armed raids on the Imperial Club and a couple of other brothels six months ago, where someone was shot, he insists this is all a frame-up.
Though when told the library door was bolted from the inside, Sanderson admits he's arrest himself too. He's not the only one. The City Commissioner is also baying for Sanderson's arrest and with good reason. The papers are printing this is a cover-up. Worse the story has spread to every corner of Melbourne. A near-riot is happening in front of the police station.
Mrs. Blunt says the only people who've been by are the regular deliveries and the electrician to check to meter, and she's miffed at having to prove her alibi. On the other end, Madame Lyon (Belinda McClory) of the Imperial Club is also unimpressed at being questioned. She tells Fisher that Sanderson was never stupid enough to show his face at her establishment, even if she's quite willing to believe he'd indulge himself in private. But Lyon is willing to let Phryne go undercover if it would help. While Phryne prepares her fan dancing, Dr. Mac pops round and tells her that Sanderson was poisoned with Sydenham's laudanum, "enough to flatten an elephant."
Jack attempts to get information by coming through the front door. It fails, clearing out the guests and collecting a phony register. (Poor Collins realizes Fisher's here when Dot walks by while Lola is hitting on him.) Meanwhile, Phryne befriends Lena (Shareena Clanton), who confirms Lavinia was doing private appointments. The doorman, Maurie Burke (Jon Bryden), tells her Sanderson's raids were a cover to get the real registry. Dot tries to reach out to her sister, and Lola brings a bible as an offering. But in their fight about Lola's lifestyle, she notes Lavinia was saved, and a fat lot of good it did her. Fisher asks Lola about it later, only to learn that the man "saving" was a patron, Catholic priest Father Blackburn.
Jack's front door antics piss off someone, as he's attacked outside the station later that night. And someone was casing the Sanderson house. When bringing in her ticket to the pictures as proof of her alibi, Mrs. Blunt remarks the electrical company came round again, insisting they'd sent no one the week before. Another search of the room turns up that the bolt is maganized iron, solving how the door from the outside. Fisher's lead pushes Jack to speak to Blackburn (Lyall Brooks), a former Navy chaplain, who is one of those calling for Sanderson's arrest. But Blackburn insists Lavinia was planning on leaving the club.
As for the secret second register, Lola explains it's not a book, but items nicked from the bigwigs as proof they were there. Supposedly, there's even a police badge that belongs to the City Chief Commissioner. Fisher attempts to break into Lyon's office via the rooftop to steal it, only to find herself at the end of the barrel of Lyon's pistol. Not that she's guarding the box; it's already been stolen. She believes Lavinia took it, and the reason she let Fisher investigate was in hopes she would find it.
Add to this Lavinia having skin under her fingernails that came from someone with tattoos and Lena noting Father Blackburn was asking after Lavinia that night, and Jack is convinced he's solved the case. But even though Blackburn knew about the box, his naval tattoos are unscratched. As Jack and Fisher hit a dead end, Dot discovers the bible Lola gave her had belonged to Lavinia, and there is a letter inside, from Sanderson to Lavinia, to come to his house that night. Jack is incensed George lied to him about contacting girls at the club, but Sanderson claims her message was anonymous, and he did not write the note.
So who did? Fisher finally puts it together when she sees who was shot in Sanderson's raid: a man named Berkowicz, who looked just like Maurie Burke. Lola, who is engaged to Maurie, says he's gone down to the docks, where he used to work to get some payment for a job. Jack, Collins, Sanderson, and Fisher corner him there, where Maurie admits he killed Lavinia, but he keeps insisting they don't know the whole story. When he tries to pull something out of his pocket, Sanderson shoots, believing the man had a gun. But Burke just had money, £500.
Jack and Phryne drink to a case solved. But the episode ends with so many questions unanswered. Who paid Burke? And who has the box? One can guess, but that seems to be a mystery for another day.