Stephen thanks The Prescott Group for their generous support, and Grimmy's temper has tragic consequences.

Author and veteran Phil Klay discusses "Redeployment," his National Book Award-winning collection of short stories based on his experiences serving in Iraq.

Hip-hop artist Kendrick Lamar talks about what he learned from the West Coast rap scene and gives a world premiere performance of his untitled track.

Seth Rogen talks about North Korea's outrage over "The Interview" and the film's adorable depiction of Kim Jong-un.

The fearsome Smaug discusses Hollywood's liberal bias and shares a clip from "The Hobbit: The Battle of the Five Armies."

Journalist Sarah Koenig talks about "Serial," her true-crime show that has emerged as the most popular podcast in history.

"Into the Woods" star James Corden talks about becoming the host of "The Late Late Show" and sings a Christmas duet with Stephen.

President Barack Obama talks about voter turnout in the 2014 midterm elections and the environmental implications of the Keystone XL pipeline.

"Infections and Inequalities" author Dr. Paul Farmer discusses his work with Partners In Health, a group that provides health care to impoverished people all over the world.

Director Christopher Nolan shares a clip from "Interstellar" and discusses his love for making thought-provoking films and occasionally blowing things up.

Singers Tony Bennett and Lady Gaga describe the origin of their creative collaboration.

Senator John McCain weighs in on U.S. military intervention in Syria and discusses his book "Thirteen Soldiers."

Jon Stewart discusses "Rosewater," his film based on journalist Maziar Bahari's arrest and imprisonment in Iran.

Nobel Prize-winning author Toni Morrison shares her thoughts on race and describes what motivated her to become a writer.

Eva Longoria discusses "Food Chains," her documentary about the exploitation of farm workers in America.

Vermont Senator Bernie Sanders discusses the shortcomings of America's health care system and gives his take on why the Democrats lost in the 2014 midterm elections.

Jennifer Lawrence chats about her archery skills, growing up in Kentucky and her role in "The Hunger Games: Mockingjay - Part 1."

Terence Tao, a UCLA professor and winner of the 2015 Breakthrough Prize in Mathematics, discusses his lifelong fascination with mathematics and the mysteries of prime numbers.

"The Woman I Wanted to Be" author Diane von Furstenberg discusses her life as a fashion designer and her reality show, "House of DVF."

"Watch What Happens: Live" host Andy Cohen shares stories from his playful memoir, "The Andy Cohen Diaries."

"How We Got to Now" author Steven Johnson discusses the tremendous impact of six innovations, including clean drinking water and air-conditioning.

Democratic Senator Kirsten Gillibrand discusses her goal of finding common ground with Republicans, legalization of marijuana and her memoir, "Off the Sidelines."

"The Dish" blogger Andrew Sullivan shares his thoughts on the 2014 midterm elections and the Republican takeover of the Senate.

"The Stranger" author Chuck Todd chats about hosting "Meet the Press" and weighs in on the midterm elections.

The International Rescue Committee's David Miliband discusses the facts about Ebola and his organization's humanitarian efforts in West Africa and Syria.

Jill Lepore talks about "The Secret History of Wonder Woman" and explains how the character was inspired by early 20th-century feminism.

"Liar's Poker" author Michael Lewis discusses the questionable ethics of Wall Street and plays a high-stakes game with Stephen.

Meredith Vieira talks about "The Meredith Vieira Show," her friendly brush with Ebola and her tendency to blurt out personal information on television.

"Excellent Sheep" author William Deresiewicz argues that Ivy League schools are failing to provide students with the tools needed for a full and meaningful life.

Writer-director Justin Simien shares a clip from his film "Dear White People" and talks about the concept of microaggression.

"Special Deluxe" author and musician Neil Young chats about his passion for cars, the Pono music player and protecting the environment.

"The Innovators" author Walter Isaacson discusses the history of the computer, the importance of hackers and the blurry line between collaboration and intellectual piracy.

Musician Robert Plant discusses his ongoing creative quest, the limited perks of being a Commander of the British Empire and his album "lullaby and... The Ceaseless Roar."

Carol Burnett looks back on her time on "The Carol Burnett Show" and describes her role in Broadway's "Love Letters."

The New Republic's Leon Wieseltier discusses the anthology "Insurrections of the Mind" and the importance of rational thinking in a democratic society.

"Embattled Rebel" author James M. McPherson talks about Confederate President Jefferson Davis and weighs in on why the North won the Civil War.

"Sally Ride" author Lynn Sherr discusses the life and legacy of NASA's first woman in space.

Former Chairman of the Joint Chiefs of Staff Mike Mullen discusses the challenges posed by ISIS and the disconnect between the U.S. military and the rest of American society.

Jeffrey Tambor shares a clip from "Transparent" and patiently helps Stephen understand the concept of being transgender.

Chef Jamie Oliver chats about his book "Jamie Oliver's Comfort Food: The Ultimate Weekend Cookbook" and trades favorite childhood dishes with Stephen.

"The Marshmallow Test" author Walter Mischel explains the relationship between delayed gratification and a person's overall success in life.

Bill Cosby describes the origin of his pocket insignia and the terrifying nature of amusement park funhouses.

"This Changes Everything" author Naomi Klein argues that capitalism is one of the driving forces behind climate change.

The father-son duo from Tweedy discusses their album "Sukierae" and ponders whether they could take Billy Ray and Miley Cyrus in a fight.

Director Terry Gilliam chats about "The Zero Theorem," his film about a man tasked with proving that everything is meaningless.

Viggo Mortensen chats about his wide variety of creative pursuits, shares a clip from "The Two Faces of January" and speaks in an Elvish accent

Teen heavy metal band Unlocking the Truth shares the inspiration behind their name and discusses their EP, "Free As You Wanna Be."

Mindy Kaling, creator and star of "The Mindy Project," talks about playing an ob-gyn on television and whether or not her show should tackle controversial medical topics.

Lonn Taylor, co-author of "The Star-Spangled Banner: The Making of an American Icon," details the history of the national anthem and the battle that inspired its lyrics.

Former Secretary of State Henry Kissinger discusses his book "World Order" and predicts the outcome of Barack Obama's speech about ISIS militants.

Jason Segel describes the origins of his children's book, "Nightmares!," and offers advice on how to end a television show after a nine-year run.

John Lithgow chats about his role in "Love Is Strange," a film about an older gay couple who faces discrimination after getting legally married.

"The Bully Pulpit" author Doris Kearns Goodwin describes the domestic challenges faced by Presidents Theodore Roosevelt and William Howard Taft.

"What If?" author Randall Munroe chats about the origins of his webcomic "xkcd" and helps Stephen determine the weight of Canada.

"Homeland" star Mandy Patinkin discusses the re-emergence of his beard and offers his antidote to the troubling state of the world.

Street artist and TED Prize winner JR shares examples of his provocative and often dangerous work in Brazil and the Middle East.

"Masters of Sex" star Michael Sheen talks about his role as Dr. William Masters, a pioneering sex researcher in the 1950s.

Jeff Bridges and Lois Lowry chat about the film adaptation of "The Giver" and ponder the pros and cons of human memory.

Airbnb co-founder and CEO Brian Chesky describes his company's emergence as a global enterprise and weighs in on the larger implications of the sharing economy.

Michael Fassbender discusses his role in "Frank," a film about an eccentric band leader who wears a papier-mache head.

James Cameron chats about his film "Deepsea Challenge 3D," which documents his record-breaking journey to the deepest point in the ocean.

"The Greatest Comeback" author Pat Buchanan offers a firsthand account of President Nixon's handling of the Watergate scandal. "The Nixon Defense" author John W. Dean discusses the extent of President Nixon's knowledge of the Watergate break-in and ensuing cover-up.

Partnership for Educational Justice founder Campbell Brown argues for the need to do away with teacher tenure in New York's public schools.

James Franco discusses the themes of his movie "Child of God" and chats about his preference for staying busy.

Jon Batiste talks about his album "Social Music" and provokes Stephen into demonstrating his improvisation skills.

Beck talks about his album "Morning Phase" and offers an impromptu description of his eclectic musical style.

Tesla Motors and SpaceX CEO Elon Musk talks about his many technological innovations, from high-performance electric cars to reusable rockets.

Mary Mazzio and Oscar Vazquez share a clip from "Underwater Dreams," their documentary about four undocumented high school students who won a NASA-sponsored robotics contest.

The New Republic's Julia Ioffe discusses Ukraine's ongoing conflict with Russia and the conspiracy theories surrounding the Malaysia Airlines Flight 17 crash.

House Democratic Leader Nancy Pelosi weighs in on the child immigration crisis and the Republican lawsuit against President Obama.

"Rattling the Cage" author Steven M. Wise makes the case for giving animals the same legal rights as humans.

Mayor Bill de Blasio discusses the challenges of income inequality, the rising cost of living in New York and his goal of providing a full-day pre-K program.

Vint Cerf reflects on the unexpected mass popularity of the Internet and the challenges that come with maintaining it.

Jad Abumrad and Robert Krulwich describe their experimental approach to storytelling in their Peabody Award-winning radio program, "Radiolab."

Paul Rudd chats about his movie "They Came Together" and its satirical take on romantic comedies.

Congresswoman and civil rights veteran Eleanor Holmes Norton explains the significance of the 50th anniversary of Mississippi's Freedom Summer.

Edie Falco chats about her role on Showtime's "Nurse Jackie" and reflects on the motivations of her character in HBO's "The Sopranos."

Author John Green discusses the emotional experience of writing "The Fault in Our Stars" and the community outreach initiatives of his YouTube channel, VlogBrothers.

Jay Carney chats about his love for contentious press briefings and shares his biggest regret as White House press secretary for the Obama administration.

"The Confidence Code" authors Katty Kay and Claire Shipman describe the long-term effects that a lack of confidence can have on women's careers.

Attorneys David Boies and Theodore B. Olson discuss their advocacy for same-sex marriage rights and their book "Redeeming the Dream."

The Atlantic's Ta-Nehisi Coates discusses "The Case for Reparations" and the ongoing history of institutional racism in America.

"I Heard My Country Calling" author James Webb shares highlights from his many years serving in both government and the military.

Soylent CEO Rob Rhinehart discusses the origins of his food substitute and shares a sample with Stephen.

Director John Waters ponders being the oddest figure in American culture and shares hitchhiking stories from his memoir "Carsick."

"Mating in Captivity" author Esther Perel explores the complex and often unconscious desires that can drive people to have affairs.

Rock legend Chrissie Hynde chats about being inducted into the Rock and Roll Hall of Fame and her status as a citizen of the world.

"22 Jump Street" star Jonah Hill describes his love for performing both comedy and drama and reveals that Channing Tatum is unfairly funny.

Morgan Freeman describes the difference between scientists and actors and shares a clip from Science Channel's "Through the Wormhole."

"Capital in the Twenty-First Century" author Thomas Piketty argues that rising income inequality is harmful to the global economy.

Secretary of the Navy Ray Mabus expands on the importance of maintaining a robust naval force and ponders a bold suggestion from Stephen.

"X-Men: Days of Future Past" star Patrick Stewart discusses knighthood, time travel and the secret to his perpetual youth.

Matthew Weiner chats about the final season of "Mad Men" and offers insight into the complex and often troubled personality of Don Draper.

"A Fighting Chance" author Elizabeth Warren discusses the erosion of America's middle class and makes the case for tougher regulation of the banking industry.

Thomas Friedman discusses ways to minimize the effects of global warming and shares a clip from the documentary "Years of Living Dangerously."

Keri Russell discusses her complex role in FX's "The Americans," a drama about two Russian spies living in America in the 1980s.

The Black Keys discuss Stephen's prostate and the power of Jerry Garcia.

"No Place to Hide" author Glenn Greenwald argues that the NSA engages in suspicion-less spying on Americans and non-Americans alike.

"X-Men: Days of Future Past" star Ellen Page discusses her emotional coming-out speech and generously helps Stephen boost his ratings.

David Remnick describes "The 40s" and The New Yorker's evolution from a comedy magazine to a groundbreaking source of investigative journalism.

Bette Midler chats about the reissue of her memoir, "A View From a Broad," growing up in Hawaii and making a successful career out of being "divine."

"A Window on Eternity" author Edward O. Wilson explains why he chose to study ants and describes the uniquely rich biodiversity of Mozambique's Gorongosa National Park.

Poet, actor and musician Saul Williams chats about his role in the Tupac Shakur-inspired musical, "Holler If Ya Hear Me."

Tony Award-winning singer Audra McDonald chats about her Broadway role as Billie Holiday in "Lady Day at Emerson's Bar & Grill."

Director Robert Rodriguez discusses his Latino-focused cable network El Rey and shares a clip from "From Dusk Till Dawn: The Series."

Former U.S. ambassador Michael McFaul discusses Vladimir Putin and the challenge of rebuilding a working relationship with Russia.

George Saunders chats about the often-overlooked power of kindness and his book, "Congratulations, by the way."

University of Kentucky Coach John Calipari shares insights from his book "Players First" and weighs in on whether college athletes should be paid.

George Will shares insights from "A Nice Little Place on the North Side," his book exploring the 100-year history of Wrigley Field.

Filmmaker Ken Burns discusses his documentary "The Address" and expands on the historical significance of Lincoln's Gettysburg Address.

Sting chats about the origins of his Broadway-bound musical, "The Last Ship," and explains his passion for rainforest preservation.

Facebook COO Sheryl Sandberg shares insights from her book "Lean In" and makes the case for encouraging young girls to become leaders.

Renowned scientist Jane Goodall discusses her book "Seeds of Hope" and explains why she shifted her research focus from chimpanzees to plant life.

"Love and Math" author Edward Frenkel makes the case for appreciating the inherent beauty and power of mathematics.

The New York Times's Mark Mazzetti discusses "The Way of the Knife," his book detailing the CIA's expansive secret military campaigns since 9/11.

ABC News correspondent Dan Harris describes how an on-air panic attack led him to begin using meditation as a way to reduce stress and focus on the present.

John Malkovich discusses his role in "Cesar Chavez," the importance of labor rights and his natural fragrance.

Twitter cofounder Biz Stone chats about the origins of his book "Things a Little Bird Told Me" and discusses his social app, Jelly.

Director Darren Aronofsky discusses his movie "Noah" and expands on the mythic power behind the epic Bible story.

Errol Morris shares insights from "The Unknown Known," his documentary about Donald Rumsfeld's role in the Iraq War.

Stephen takes Jimmy Carter to task for his liberal ways, and the former president expands on his book "A Call to Action."

Bryan Cranston discusses his role as Lyndon B. Johnson in Broadway's "All the Way" and reflects on LBJ's habit of talking about his balls.

Historian Simon Schama discusses "The Story of the Jews," his PBS documentary exploring Jewish history from 1000 B.C. to 1492.

Maria Shriver expands on "Paycheck to Paycheck," her HBO documentary about working mothers on the brink of poverty in America.

Ronan Farrow discusses digital media as a tool for civic action and his MSNBC show, "Ronan Farrow Daily."

Neil deGrasse Tyson discusses his lifelong passion for astrophysics and shares a clip from his science series, "Cosmos."

Chicago artist Theaster Gates expands on his efforts to beautify abandoned spaces and revitalize poor neighborhoods.

"House of Cards" creator Beau Willimon discusses his award-winning series and its depiction of power, corruption and intrigue in Washington politics.

"Who Owns the Future?" author Jaron Lanier discusses the challenges of creating a fair and sustainable economy in the digital age.

The Atlantic's Caitlin Flanagan shares insights from her year-long investigation into campus Greek life for her article, "The Dark Power of Fraternities."

"The Grand Budapest Hotel" star Jeff Goldblum describes the unique experience of working with director Wes Anderson.

U.S. gold medalists Meryl Davis and Charlie White discuss their lifelong dedication to ice dancing, their rare chemistry on the ice and the power of Charlie's hair.

Singer-songwriter St. Vincent chats about her siblings and shares her views on art and self-identity in the digital age.

Darlene Love chats about "20 Feet From Stardom," the Oscar-nominated documentary that explores the lives of background vocalists for famous singers.

"My Share of the Task" author Stanley McChrystal reflects on the future of Afghanistan and explains why he supports bringing back the draft.

Alexander Payne discusses living in America's heartland, his preference for road trips and his Oscar-nominated film, "Nebraska."

World Science U founder Brian Greene discusses using the Internet to teach physics and gives an overview of Einstein's theory of relativity.

Filmmaker Godfrey Reggio expands on his unique approach to cinema and shares a clip from his movie "Visitors."

Former governor of Florida Charlie Crist discusses his book "The Party's Over" and explains how the rise of the Tea Party drove him to become a Democrat.

Patrick Kennedy discusses equal insurance rights for the mentally ill and his anti-marijuana lobbying group, Project SAM.

Pulitzer Prize-winning economist Paul Krugman addresses the claim that Obamacare will destroy jobs and argues that the program will benefit everyone.

The members of indie band Lake Street Dive chat about their jazz roots, their eclectic musical style and their album "Bad Self Portraits."

Pussy Riot members Nadya Tolokonnikova and Masha Alyokhina recount being imprisoned for singing in a church and share their views on Vladimir Putin's harsh anti-gay laws.

"All Joy and No Fun" author Jennifer Senior examines the bittersweet joy of raising children and explores how the dynamics of parenthood have changed over the years.

New Orleans Saints' Drew Brees shares the challenges of being an NFL quarterback, his secret to "owning the room" and his Xbox game, "Playoff/Faceoff."

"Going Deep" author Cris Carter describes the responsibilities of a wide receiver, the hazards of pileups, and the perks of being an NFL Hall of Famer.

The New York Giants's Justin Tuck describes the euphoric thrill of smashing into people and makes a prediction for the 2014 Super Bowl.

FiveThirtyEight Blog's Nate Silver explains his return to sports analysis at ESPN and shares his predictions for the 2014 Super Bowl.

"Touching a Nerve" author Patricia Churchland explores ways that neuroscience can answer philosophical questions.

"The Power of Habit" author Charles Duhigg explains how habits play a constant role in human behavior.

"Telegraph Avenue" author Michael Chabon discusses Hemingway's innovative writing style and ponders the lack of sexy-time in "A Farewell to Arms."

"My Age of Anxiety" author Scott Stossel shares his idiosyncratic phobias and discusses the origins of human anxiety.

"Fast Food Forward" member Naquasia LeGrand discusses organizing strikes for her fellow fast-food workers and argues for increasing the minimum wage.

"The Loudest Voice in the Room" author Gabriel Sherman discusses the larger-than-life personality of Roger Ailes.

Art critic Deborah Solomon talks contemporary art and shares insights from her Norman Rockwell biography, "American Mirror."

The Iraq War debate continues, marketing gets an upgrade, and David Fanning is the executive producer of PBS's Frontline.

Participant Media's Jeff Skoll discusses his mission to create films that raise awareness of important issues.

Author and former child soldier Ishmael Beah explains how he was recruited into the Sierra Leone military at 13 years of age.

Veteran news anchor John Seigenthaler talks about his move to Al Jazeera America and the network's emphasis on serious news.

Human Rights Watch's Ken Roth discusses his organization's mission to end human rights violations around the world.