Tuesday’s finale of “American Crime Story: The People vs. O. J. Simpson” on FX wrapped up an addictive, multifaceted look at “the trial of the century” and how its lessons on race, gender, celebrity and social class still haunt the country more than 20 year later. It also brought a blessed end to the weekly torments visited upon Christopher Darden, the co-prosecutor who, along with Marcia Clark, fails to convict Mr. Simpson of double homicide in the murders of Nicole Brown Simpson and Ronald Goldman.

[Recap: “The People v. O.J. Simpson” Finale]

As Mr. Darden, the actor Sterling K. Brown has been the agonized face of a sure-thing prosecution gone horribly awry. Mr. Brown exposes the raw emotions of a man whose commitment to justice was answered by setbacks, ridicule and, finally, a “not guilty” verdict after only four hours of deliberation.

Though Mr. Brown has found consistent work in television and film for more than a decade, his performance stands to be the one true breakthrough in a cast loaded with familiar faces. On the weekend before the finale, Mr. Brown chatted on the telephone about Mr. Darden’s terrible poker face and the experience of being part of a water-cooler show. These are edited excerpts from the conversation.