Sarah Koenig's Serial has been downloaded nearly 100 million times. And that's before season two launches this month. Get addicted here.

Her Words to Live By: "My father used to say, 'Take what you want and pay for it.' I took it to mean: Be accountable for everything you do. Be able to answer for it." —Sarah Koenig, here in her "office" in Sag Harbor, New York. Read that blackboard for clues!

Inside a weathered garden shed in Sag Harbor, New York, Sarah Koenig works at a large U-Haul box on which she's set up her laptop and cell phone, with a blackboard to her right that has a few random—or maybe not so random—notes like "figure out Thursday" and "noose." It's here in this tiny shack that season two of the podcast Serial is coming to life, the follow-up to the real-time true-crime investigation that won a Peabody Award, helped reopen a murder case, and single-handedly made podcasting a thing.

"Some of our cast was so obsessed with Serial that we drove to all the locations mentioned—Woodlawn High, Best Buy, Leakin Park… Serial was the perfect blend of journalistic rigor and imaginative storytelling. It revolutionized podcasting and showed us all what was possible."

—Beau Willimon, creator of Netflix's House of CardsKoenig first learned "the rhythm and humor of words" from her adman father, Julian Koenig, and her novelist stepfather, Peter Matthiessen. Later she developed her own following as a producer for 11 years at the public radio show This American Life. But it wasn't until she cocreated the spin-off podcast Serial that Koenig, 46, became a household name. Over the course of 12 episodes last fall, she got the nation hooked on the 1999 homicide of Baltimore high school senior Hae Min Lee—a case Koenig had first learned about when she was contacted by a friend of Lee's ex-boyfriend, Adnan Syed, who is serving a life sentence for the crime. "Honestly, at first I didn't know whether it was a good story," she says. "But I couldn't shake it. I was like, 'What if he is innocent and someone should be doing something about it? Wait, that someone could actually be me.'"

Week after week, Koenig dug up old leads and new information, asking: Did Syed really do it? "I was so consumed," she says. "I'd talk to anyone who'd listen. Nobody cared back then." But within a few episodes, people cared. A lot. More than 20 Serial subreddits sprang up; Stephen Colbert called Koenig his "favorite guest of all time"; she was even spoofed on Saturday Night Live. Serial quickly became the most-listened-to podcast in history—and lit up the whole medium (7 million more Americans a month now tune in to podcasts than before the show began). Koenig's reporting also helped reopen the case: Syed has been granted the right to appeal.

"Sarah wasn't a Sherlock Holmes; she was one of us—down-to-earth and very relatable, " says David Bushman, a curator at The Paley Center for Media. "And we were able to experience the mystery with her and through her." Now the mother of two is racing to finish the second season, set to air in November, while (FYI to fans) she's also reporting on season three. "I'm stressed, and I see my children less than I'd like to," she says. "But I like that they are seeing their mother work really hard at something she loves and getting the lesson that they can go do the thing they want to do." She won't reveal any spoilers about the next season: "It's our take on a news story that's already caused a lot of brouhaha," she says. "It's controversial." Get ready to binge-listen.