The Last Laugh opens with a quote onscreen from the noted non-comedian, German novelist Heinrich Mann, who wrote: “Whoever has cried enough, laughs.” Mann fled Nazi Germany while Hitler’s soldiers burned his books in public.

The documentary then cuts to a Nazi-uniformed figure skater, then to present day.

Yes, this is going to be about Jews and the Holocaust. Which somehow feels much more relevant in 2017 than it did in 2016, when The Last Laugh premiered at the Tribeca Film Festival. After a successful festival circuit, the film began its theatrical run two weeks ago in New York City, and opens today in Los Angeles at various Laemmle locations. Director Ferne Pearlstein will answer questions following screenings tonight and Saturday at the Music Hall location, and Sunday afternoon at the Town Center cinema, joined by various producers and participants. If you can’t make those or otherwise miss out, the doc will eventually make it to TV on PBS in April.

Let’s start with the last word on the last laugh, courtesy of the one and only Mel Brooks: “Comics are the conscience of the people, and they are allowed a wide berth of activity in every direction. Comics have to tell us who we are and where we are, even if it’s in bad taste.”

Inspired by a 40-page paper, “The Last Laugh: Humor and the Holocaust,” written by one of the director’s friends, Kent Kirshenbaum, as a PhD dissertation in the 1990s, Pearlstein wanted to explore taboos in humor, starting with the Holocaust and eventually branching out to include discussions about envelope-pushing in general and specifically with regards to AIDS, racism, 9/11 and other subjects and events.

We’re reminded of the Holocaust, though, throughout the documentary. From the start, we see two women having an impromptu picnic outside an old Nazi bunker, now overrun with weeds and graffiti. Later, we learn the older of those two women survived the Holocaust, and the younger is her daughter, and we watch several comedians joke about the Holocaust via contemporary video clips while mother and daughter decide whether the jokes are funny, too soon, or just plain offensive.

Gilbert Gottfried and Rob Reiner help jump-start the documentary’s actual comedy by telling a joke about Jews sent to assassinate Hitler, while Brooks, as seen in the trailer above, wonders what the documentary is asking of him, exactly. “So what is this supposed to be? Crossing lines? Being in bad taste? So shall I start the interview with (puts comb to mustache) Heil Hitler?! Is that good? OK.”

Of course, the comedians have other ideas about what’s funny and what’s allowed to be funny in the first place.

Take Judy Gold, for instance: “It’s all about the funny. It’s got to be funny. You can’t tell a crappy joke about the biggest tragedy in the world. You can’t do it.” Sarah Silverman and Carl Reiner agree.

Robert Clary, who entertained fellow Jews as a teen in the concentration camps during World War II, later would co-star in Hogan’s Heroes, 20 years later, as a cut-up one of the WWII POW camps. In between the war and Hollywood, Clary met Brooks. “That was second nature with me: Singing, dancing, clowning around,” Clary says. “That helped me tremendously when I was deported. Because automatically, even the first camp I started singing for the people who were there, the prisoners.” Clary was the only one in his immediate family of 13 to survive the Holocaust. In the Catskills of the 1950s and 1960s, however, the Jewish-American families didn’t want to hear jokes that anything to do with their relatives who didn’t make it.

At a Holocaust survivor’s conference much more recently in Las Vegas, some said humor was the only thing that got them through it; others saw only sadness and tragedy.

Jeffrey Ross, the “Roastmaster General,” empathizes: “By making these jokes, it’s the Jewish way of getting through it.”

Added Brooks: “Anything I could do to deflate Germans, I did.” But Brooks gets the other side, too, noting that it took multiple centuries to pass before everyone could be OK with Spanish Inquisition jokes. And Harry Shearer pointed out the irony that The Producers, the Brooks classic film about a Broadway flop could decades later become an actual hit on Broadway, with much less irony in gleefully singing “Springtime for Hitler.”

Survivor/educator Renee Firestone is shown reminding students at the Museum of Tolerance how society once viewed Hitler as a satirical character and underestimated him. “In 1933 when I was 9 years old, I went to my father and I asked, ‘Is it possible that this man is claiming that he’s going to kill all of us?’ And my father said, ‘Don’t listen to that comedian. Don’t you see? He looks like Charlie Chaplin. He’s going to be out of office in no time.’ Well, my father was wrong. They packed us into cattle cars.”

The comedians emphasize once more that to tackle a taboo subject, it’s much better and more effective to make the joke about something else. The taboo subject is never the premise, the villains always the target. “Auschwitz is a funny punchline, but not a funny premise,” Ross said.

Which leads to a side discussion and comic-on-comic mockery of the films Life is Beautiful and The Day The Clown Cried.

Less unanimous are opinions on whether NBC should have allowed Seinfeld to popularize a character called Soup Nazi, whether Jack Benny did more harm than any other comedian in creating and perpetuating a stereotype of Jews as cheap, why Dave Chappelle decided to step away from Chappelle’s Show, and whether the cowboys laughing at Borat in Da Ali G Show‘s anti-Semetic song were laughing at irony or laughing along with prejudice. As Silverman, who’s made a career of pushing the envelope, observed: “You can’t control how your joke will be inferred.”

So who’s allowed to make which jokes when and where?

Are Amy Schumer, Chris Rock, Lenny Bruce, Leslie Jones, Ricky Gervais, Family Guy, South Park, Louis CK, Woody Allen, and the like crossing the line or not? It depends upon where and whether you draw lines in the proverbial sand that cannot be crossed by a comedian.

“Sometimes it’s important to be ahead of society,” David Steinberg tells the filmmaker. “Just because it’s uncomfortable, doesn’t mean it’s the wrong thing. Sometimes it’s exactly the right thing.”

The Last Laugh opens today around Los Angeles, with a national rollout to follow, and a PBS premiere in April.