It's the morning after "The Daily Show" broadcast live for the midterm elections, including a sketch that reported from the campaign headquarters of the night's big winner – Money, as played by a hard-partying Rob Riggle – and the desolate base of the night's loser, Ideas.
Humor, Stewart says, is an "amoeba-like substance" that can grow in even the harshest of conditions, like life at the bottom of the ocean.
"It may be grotesque and absurd life. It may be a fish with a crab growing out of its head that lights up like a Lite-Brite," says Stewart. "But it's there."
For 16 years on "The Daily Show," Stewart has found comedy by wading through the muck of TV news, partisan politics and some horrific current events. "Rosewater" may seem like a story far afield from the satire practiced on the "The Daily Show," but Stewart was drawn to the true tale by Bahari's levity in recounting his 118 days imprisoned and tortured after reporting on Iran's 2009 elections.
In his memoir, "Then They Came for Me," Bahari (played by Gael Garcia Bernal in the film) relates an uncommon sympathy for his interrogator, recognizing the absurdity of an authoritative regime that would so desperately fear his opinions. In a film about preserving one's sanity in an insane system, the moment of triumph is a joyful, overflowing laugh.
"It's a process that I need to use for myself," says Stewart. "That's the way I process events."
"Rosewater" is a subtle mission statement of Stewart's worldview, one where humor is an essential tool for disarming the powerful, for claiming one's humanity.
"Certainty is the enemy of humor," says Stewart. "Authoritative regimes are nothing if not certain and dogmatic. One of the things about ('The Daily Show') is a lack of certainty. It really is confusion being worked out through whatever silliness we've thrown out there."
Stewart was connected to Bahari because he appeared in a segment by "Daily Show" correspondent Jason Jones, filmed in Iran. (The footage was later treated as evidence that Bahari was a spy.) After Bahari was released, a friendship developed between him and Stewart.
Stewart offered to help Bahari get his book adapted into a film, but when four months went by without interest, an impatient Stewart wrote the script himself. He would meet Bahari at 7:30 a.m. for breakfast to go over notes, and write in the evening after taping "The Daily Show" and putting his two kids to bed.
"I basically did what we do here: I threw a bunch of cards up on the board and I structured it," says Stewart of his first stab at screenwriting.
Stewart shot the film last summer in Jordan while on hiatus from "The Daily Show." In extreme heat, working with a largely international cast and with a small budget, the novice director summoned naturalistic performances from his actors.
"Once you've survived doing stand-up at a Fuddruckers outside of Rochester, Jordan is much more luxurious," says Stewart.
Returning to "The Daily Show," he moved the film's editor into a coat room at the show's offices. In between work on the show, he ran and up and down floors to sneak in editing sessions.
"There were definitely moments where I thought, 'OK, you always wondered just how far you can push this. Well, now you know,'" says Stewart.
But the results are impressive, particularly for a first-time filmmaker. Stewart, said The New York Times, "turns out to be a real filmmaker."
"Who knew?" says Steve Carell, the former "Daily Show" correspondent. "I had no idea he was a filmmaker, and he is. Right out of the block, he has a voice and a style."
Part of what makes "Rosewater" unique is its resistance to Hollywood-izing Bahari's tale. Just as Stewart – ever a champion of nuance – laments the media's penchant for exaggeration, he recoiled at making "a one-dimensional, victim-versus-monster torture-porn movie."
"There's an infrastructure of torture that is officious, business-like, absurd, Kafkaesque," says Stewart. "Violence is there, but there is a much broader context that it all lives in."
Bahari, who now lives in London, says he and Stewart share a resentment of those who believe they have "a monopoly on truth."
"It's futile to regard a government or a person as a monster or evil," says Bahari. "There's no evil or monster. There's just human beings in bad systems."
Will Stewart, whose Comedy Central contract is up next year, make another movie? The form he operates in, he says, doesn't matter.
"It's a journey. It's a conversation," says Stewart. "One thing I won't do is write music or sing."