Cain is remembering his days as a detective in 1958. He was working on the case of the broken hearts killer. Or something.
Chloe is going by his cues as to whether to admit if she liked the Azara concert or not. Cain wants to do it again, but before they can make plans, Dan interrupts with news of a case.
When a barista asks Amenadiel what he wants, he starts telling her his problems as if she's Linda or a therapist. Then Charlotte grabs a coffee and Amenadiel runs out of the coffee shop calling after mom. When he talks about Lucifer sending her away with the flaming sword, etc., he realizes she isn't mom. Charlotte, though, is interested in what he has to say. Amenadiel excuses himself and apologizes.
Cain says one of his mentors was involved with the case in 1958. The Broken Hearts Killer used to force married people to swallow their wedding rings before smashing their chests and their hearts.
Dan gets to Chloe's house and discovers Maze wasted with members of a band passed out all over the house, including in Trixie's bed. He wants her to get her act together.
Cain apologizes to Lucifer tor coming between him and Chloe. He didn't know they had a thing.
The team goes on a Broken Hearts tour and discovers a suspect. Since they're near the restaurant Cain frequented the first time he investigated the case, he stops in and is stopped in his tracks. Kay is behind the bar. Or is she a descendant?
Amenadiel goes to see Linda to break the news to her about Charlotte.
Nana's husband was the detective who solved the Broken Hearts case. He may have caught the killer red-handed, but he never learned how he chose his victims and it bugged him for the rest of his life.
Then it turns out Neil isn't the killer at all. Officer MacMillan over in vice sold him a box of photographs. That's how he knew about the case.
Inside, Cain has decided he wants to let himself be open to Chloe. Before she can answer, they pass out. The killer comes in and Lucifer rescues them, but not without learning another lesson. He cannot just decide who people should be with any more than the original Broken Hearts Killer.
Amenadiel decides Charlotte deserves to learn the truth. He starts by telling her she was his mother.
Chloe gets home to Olga. Maze has moved out.
Lucifer gives Chloe his blessing to have a relationship with Cain. That was unexpected.
Dan lashes out at Maze after Trixie takes pot brownies to her teacher for Teacher Appreciation day. Maze acts inappropriately in response and decides to move out. In the process, she calls Trixie and Chloe names which Trixie hears sending her away in tears.
Cain wants to borrow Ray's notes to help solve the modern day case.
Cain remembers the past and letting down Kay easy. Now he sits in the same table across from Chloe. Ray learned every couple in the past listened to and called in to a jilted lovers radio show.
Ella loves listening to a show on the air nowadays. Of course. Chloe and Cain set up as a couple with Lucifer as the jilted lover. When Cain treats the date like a real second date, she's a little surprised. He even makes her favorite dish. But Chloe needs someone who can let her in, and she doesn't know it that's him. We know it's not Lucifer.
Lucifer went to Dan to ask how Dan got over Chloe when Lucifer showed up. Dan realized that they're different people and their relationships are different, too. When that was clear, he was OK.
The pastrami kid from the radio shows appears at Cain's to film the boyfriend busting up the date. He posts them unedited on his website. THAT's how they're getting the addresses.