"I think this is the first cartoon/crossword puzzle crossover ever," laughs Al Jean, teasing this Sunday’s (Nov. 16) Very Special Episode of The Simpsons.

Titled "Homer and Lisa Exchange Cross Words," the episode plays off one of The Simpsons‘ recurring character tropes, the fragile trust between Homer and Lisa, a dynamic that has played out across beauty pageants, singing competitions and museum visits over the years. This installment began with James L. Brooks’ desire to do an episode about crossword puzzles.

"We all liked the documentary Wordplay and we thought it’d be interesting if Lisa got addicted to crossword puzzles and entered a contest and knew that she would probably blow it since she always sabotages herself. So Homer bets against her and wins," explains Jean, one of the series’ most venerable producers. "Tim Long wrote the script and talked with the New York Times about doing a crossover where they actually had the crossword puzzle from the New York Times on the show and Homer puts a secret message to Lisa in the diagonals, which you see at the end of the episode."

So, in an unusual gesture, the Paper of Record turned over its Sunday puzzle, the Holy Grail for crossword aficionados, to The Simpsons. Lest amateur cruciverbalists get up in arms, though, the puzzle was created by Merl Reagle and overseen by genre legend Will Shortz.

"It’s still done by the people who do the puzzles," Jean promises. "All we wanted was to have this message from Homer to Lisa in the puzzle, which is there. Then they wrote a puzzle around that. What they said was that they weren’t going to promote it as a Simpsons thing, but they’d do it."

He adds, "It’s great. It looks like a real puzzle. You could do the puzzle and never know there was a connection."

In addition to working on the puzzle, Reagle and Shortz pop up for vocal cameos, joining the ranks of unexpected and oddball Simpsons guest voices.

"I don’t think there’s anybody better at playing Will Shortz than Will Shortz," promises Jean, who admits his own intellectual interests tend more toward chess than puzzles. "What we like to do is get guest voices who either are terrific actors, like this coming year we’ll have Anne Hathaway and Jodie Foster and Emily Blunt, or people that you don’t see on other TV shows, like Will Shortz or Tony Blair or Thomas Pynchon, people who make you go, ‘Wow, it’s very interesting to have them on a television show.’"

Wordplay, a 2006 documentary hit, is just the latest unscripted feature to inspire the Simpsons team. Recent seasons have seen episodes built around Michael Apted’s 7-Up series, as well as the Oscar nominated Capturing the Friedmans. This isn’t about the show becoming increasingly esoteric, so much as narrative necessity.

"We’ve recorded 449 episodes, so we’re interested in good templates, especially like the 7-Up series, wherever you can find them," Jean says. "If we find something where we think it’s good and it would lend itself to our characters, we do it. I think it should be something on its on merits. Like if you do something like 7-Up, I think a lot of people liked that episode who had never seen those movies and it’s a great format where if you weren’t aware of what it was, it’s still self-explanatory. We try to do things like that and then if somebody gets it on the extra level, then so much the better."

Plenty of people are obviously still getting The Simpsons on that extra level. The show’s annual Treehouse of Horrors even scored a surprising weekly demographic win.

"This was the first time, ever, that we’ve been No. 1, we were No. 1 in 18-49 viewers with a 6.2. It’s amazing," Jean raves. "We [took out an ad that] said, ‘FOX is shocked that after 20 years that The Simpsons is finally No. 1.’ First of all, there’s only one other show that’s ran for 20 years and this has never happened, that a show was 20-years-old and No. 1."

Other highlights on my chat with Al Jean:

On whether, as some pundits have suggested, it will be harder to find political humor in the Obama Era: "I’ll tell you, I was part of the same debate after 9/11, when we were told that there was no more satire and you couldn’t make fun of Bush anymore. That certainly was not true. I remember too when Clinton was inaugurated and Al Gore said something like ‘Well now there’s nobody to make fun of.’ Again… Times changed and they were funny. You never know what’s going to happen and you never know where it will go, but I’m sure there will be satire."

On remembering what jokes they’ve told: "Actually, the real fans, the enormous fans, have a much better memory of the show than I do. I’m just trying to get to the next one. When I was watching DVDs from shows we’d done 10 or 15 years ago, I was surprised by certain things. A couple times there have even been jokes that we’ve done more than once, like the thing where Homer said to Marge ‘Let’s make some fireworks of our own’ while they’re watching fireworks and then he actually makes fireworks with gunpowder. And we did that in, I think, ‘Kamp Krusty’ and a show called ‘Special Edna.’ That’s the most embarrassing. But we’ve done 450 shows, that’s 450 times 50, that’s like 22,500 pages of material. That’s quite a bit."

On the question he’s asked most, now that the movie finally came out: "You know what’s depressing? As soon as it came out the first thing people asked is ‘When is the sequel coming out?’ It was like, ‘Couldn’t we have a week to enjoy it?’ It’s that one and ‘When will the show end?’ The answer to the first one is that we wouldn’t want to do a sequel unless we had a script that we believed in as much as the script for the first one, which would take a while. And my only personal opinion would be that it’s better to wait until the show ended to do another movie. That goes into the second most-asked question and I would say that the show, we just completed reads for our 20th season, which will spill over into 2009, and then the cast is signed for three more years. So I would say it’s a greater-than-50-percent chance we’ll do those years as well, just because the economics are all there. After that? I don’t know. Then we’ll have run 24 years, which is four years longer than anything ever did. I would hope to keep going, but I wouldn’t be sure."

"Homer and Lisa Exchange Cross Words" will air on Sunday, Nov. 16 at 8 p.m. ET on FOX.

Posted by:Daniel Fienberg