More than a year into the litigation, the two sides are at loggerheads. Unusually for a Wall Street firm, TCW has refused to settle, alleging that Ms. Tirschwell was a difficult and underperforming employee who saw she was in trouble and lodged a sexual harassment complaint before the company had the chance to let her go. Complicating matters, Ms. Tirschwell and Mr. Ravich had been dating as recently as 2013. When she joined TCW, her ex-boyfriend was suddenly her boss.

The case is slogging its way through the court system. Discovery is ongoing, there is zero talk of cutting a deal, and unless something dramatic happens, Sara Tirschwell v. TCW Group, David Lippman and Jess Ravich could become the first major Wall Street case of the #MeToo era to go to trial.

Days in court have been rare for the movement — and rarer still for Wall Street, where grievances are typically dealt with in private, and by wire transfer, when they are dealt with at all. Ms. Tirschwell’s battle with TCW is changing that, offering an uncommon look at how sex, money and power really work in a supposedly rarefied industry. But in a case this charged — with Ms. Tirschwell and Mr. Ravich directly contradicting each other in court filings — anyone looking for a tidy outcome is bound to be disappointed.

A startling narrative

Ms. Tirschwell and Mr. Ravich first met around 1994, when she worked for a trading firm called Libra Securities, where he was the chief executive. After she left the company, they lost touch until 2011 or 2012, when they reconnected and dated for about a year.

In 2015, Ms. Tirschwell began discussing the prospect of starting a new distressed debt fund with Mr. Ravich. He was living in Los Angeles and working as head of alternative products at TCW — an influential position that empowered him to launch new offerings and make key hires. Ms. Tirschwell started consulting for TCW, then joined the company as an employee in September 2016, reporting to Mr. Ravich.

Intimate relations between employees and their managers are “strictly prohibited” at TCW, according to the company handbook. TCW was aware that Ms. Tirschwell and Mr. Ravich had once dated, and it allowed her hiring to proceed. A TCW spokesman said Mr. Lippman spoke to both Ms. Tirschwell and Mr. Ravich, and that they both pledged to keep things professional.

But by this time, Ms. Tirschwell alleges, Mr. Ravich had already been pressuring her to have sex. In her lawsuit, she claims that “in or about April or early May 2016,” the two planned to have breakfast at Jean-Georges, a restaurant located in the Trump International Hotel & Tower on Central Park West, where Mr. Ravich had an apartment.