This episode was all about Ella, but we'll start with the other characters first...
Lauren is officially a high-priced prostitute. She met with Wendy, the woman she ran into at the bar last week, and agreed to her terms as her pimp; namely, Wendy gets half of Lauren's cut and if Lauren misses a single appointment, she's done. This ought to create major problems, considering Lauren is in med school. It already created problems this week with Riley when Lauren stood her BFF up.
By the end, they were pals again and Lauren was even Riley Maid of Honor. But Riley has no idea about her friend's new line of work, of course.
Jonah almost loses his job because a man that hired him to take videos of expensive houses accuses him of stealing a necklace. At Ella's birthday party, though, Jonah thinks David committed the act. How come? He overhears David and Ella talking about a similar sounding necklace, and David has previously seen the address for the residence in question. Viewers, of course, know David is guilty.
But he denies it and then the necklace magically turns up later. Jonah feels terrible and apologizes to his friend, even though he actually had David down perfectly: this is a bored rich dude that steals for the thrill of it.
Violet, meanwhile, has fun this week in a new way. She sets up Coal'e bartender to get fired by planting money from the cash register in her purse. The plan works just as she hoped it would, as Violet is named the new bartender, at least for a night or two per week. Man, this character would be so much better if Ashlee Simpson weren't playing her.
Now, we get to Ella. As the police question her about Sydney, we see flashbacks of this pair's relationship. Sydney overheard Ella making up a story to a cop that wanted to boot her car year ago and decided to take her under her wing. The deal was this: Sydney would make Ella into a top publicist, and Ella's firm would represent Sydney's art gallery in exchange.
After a couple years, though, this arrangement went south. Sydney acted like a bitch. Ella's head gew large. As a result, Sydney was trying to ruin Ella's life (i.e. canceling her credit cards) around the time of her death. The cops have security camera footage of Ella speaking to a private detective outside the club around the time she claimed she was home doing David on the night of Sydney's murder.
Ella speaks to this private detective late in the episode and tries to get them on the same page (i.e. covering up the fact that Ella hired him to dig through Sydney's apartment), but the guy doesn't play along: at the end of the hour, the police tell Ella he's accusing her of the murder.