Early yesterday morning — Thursday, December 18th, 3:21 AM ET — a corner of the internet exploded. Reddit's /r/serialpodcast, created to serve the fanatical following of one of the most successful podcasts of all time, had already been named subreddit of the day, and by mid-afternoon, the listing and comment pages were pulling in over 80,000 page views every hour. Most redditors were pleasantly surprised by the show's last episode ("Fucking fantastic"), others grieved for the end of a show they'd grown to embrace. ("It has been one hell of a ride. I am going to miss it dearly.") In all, the subreddit got more than a million page views on the day of the finale. But now that the first season of Serial is in the can, will the Reddit devotees stay on the case, or will they dissolve into the ether of the web, and move on to the next obsession?

The debut season of Serial — which chronicles the journalist Sarah Koenig's tireless, personal, nit-picky yet captivating investigation into the 1999 murder of Hae Min Lee and the conviction of her ex-boyfriend Adnan Syed — is arguably the first podcast blockbuster. It not only draws an average estimated 2.2 million listeners per episode, but has inspired at least one so-so Miley Cyrus mash up, one slightly more respectable Biggie remix, a Funny or Die parody, and a spot for Koenig on our very own 2014 Verge 50 list. Koenig even landed a coveted spot on one of The Colbert Report's last episodes.

Serial found a particularly fertile fanbase in Reddit, where the Serial subreddit just hit 30,000 members yesterday (compare that to This American Life, with just over 2,000 subscribers). Redditors are nothing if not obsessive — perfect targets for the minute-by-minute discrepancies, countless characters, the theories, counter-theories, and conspiracies of Serial. So they threw themselves into Hae Min Lee's case wholeheartedly; one user admitted to developing a Pavlovian reaction to hearing the first notes of the podcast's theme song.

Some Redditors took it upon themselves to crack the case, going to incredible lengths to uncover some piece of evidence that Koenig hadn't, searching for proof of Adnan's innocence or else a clue that would condemn him beyond a reasonable doubt. Visit the subreddit and you'll find, among other things, a transcript of each episode, cell phone records of calls made by Adnan, a list of everyone ever mentioned in the podcast, at least 19 different maps (including a global map of all Serial subreddit subscribers), homemade "guided tour" videos of the areas featured in the podcast, polls, photos, related links, and more.

"I had never really seen a community like this one," says Jacob White, 34. When White isn't moderating the Serial subreddit, he works as a Broadway stagehand in New York City. Before stumbling onto Serial he says he had no interest in true crime, and only visited Reddit from time to time.

But as he sank into the details of the case, he needed a space to organize his thoughts. He was one of the first to join the Serial subreddit and compiled the page's character list. "It was useful for me to visually keep track of names and places," he told me over the phone. Unlike other podcasts, Serial had countless documents to pore over and obsess, scrutinize and argue over. "What made this one different,' he says, "was that people felt a connection and ability to interact with the story more than just be a passive listener."

White became a moderator, and at first took the time to read and vet every post. He and other moderators tried to keep a handle on the conversation: "We wanted to make sure that the privacy of people involved were maintained so that Redditors weren't blaming innocent people," he says. The memory of the Boston Bombings fiasco, in which Redditors quickly, and incorrectly, identified a suspect, was still fresh in everyone's mind. The community made a concerted effort to police itself, protecting identities and not offering any personal details beyond what Koenig revealed in the podcast itself. But as the number of subscribers grew, moderators lost the ability to monitor each and every conversation.

Addresses slipped out, as did last names and Facebook pages. A couple weeks ago, one Redditor admitted to The Guardian's Michelle Dean that they'd located one of the characters in the show and driven by their home. "I was just curious like everybody else," he told Dean. In the age of Google, it's not hard to become an amateur sleuth, and some couldn't resist the opportunity to launch miniature investigations of their own.

"There are users that are going to post the phone numbers and the addresses and the email addresses of anybody real connected to this case if we let them," White told me. "It's a real-life case and people can go and they can play internet detective, for good or bad."

"Investigation is like tennis," says Richard Plansky, the Executive Managing Director and head of operations in the Americas of K2 Intelligence, an international investigations outfit. "Everyone can pick up a tennis racket and hit a tennis ball. But very few people can be Roger Federer."

As a prosecutor at the Manhattan's DA office during the '90s (when New York, he says, "was a much different city"), Plansky worked on homicides and sex crimes — cases not unlike the murder of Hae Min Lee.

Plansky says that amateurs can, on the occasion, be helpful to an investigation. But they can also do more harm than good, and sometimes that harm is irreparable.

"There's a lot of trade craft here that, typically, amateur detectives don't understand," he said. "And there are also ethical and legal restrictions that amateur detectives aren't even aware of." In states like New York, conducting an unlicensed private investigation is a criminal offense. If one doesn't follow the law, any evidence gathered may be inadmissible, or else tainted.

"This is why we have the police, this is why we have federal law enforcement authorities, this is why we have federal and state prosecutors," Plansky said. "This is what they do; this is what they're trained to do. They have the tools to do it that the average person does not have. While I think it's important for everybody as citizens to do their job — meaning if they're witnesses to crime, to assist the authorities in any way they can — I don't think it's their jobs to actually conduct the investigations."

Another Serial moderator I spoke with, PowerOfYes (as a working lawyer in Australia, she asked not to be identified), told me that for the most part, Redditors weren't actually bringing much new evidence to the table. But the way she sees it, the debates and arguments of the subreddit weren't just a matter of idle curiosity, but an act of civic engagement.

"A murder is a crime against a state, not a crime against person," she said. "That's the basis on which we prosecute people. And if you are a prosecutor, you appear on behalf of the state, and that means you appear on behalf of us." To PowerOfYes, the idea that the Reddit discussions didn't have legitimacy because they involved amateurs, or that the debate over the particularities of the case somehow diminishes the memory of Hae Min Lee, is wrong. "I don't think it's right to turn away from it when you have a chance to scrutinize how the system works. It's like voting. You shouldn't vote if you don't take even a little bit of interest in what you're voting for."

As for whether she expects the same level of civic engagement (or plain old obsession) to persist now that the show's first season has come to a close, she's doubtful. Though she'll be monitoring the subreddit — as a lawyer, she's interested in the legal and systemic issues in play — she says she'd be surprised if by January there was much activity on the site at all. Even though Adnan still sits in a Maryland prison, there's no reason for anyone except the hardcore to come back to the subreddit. "Now that the show's over," she said, "there's nothing new to discover."

Not that there haven't been efforts made to create a more lasting legacy. A few days before the podcast's final episode, moderators on the subreddit launched the Woodlawn High School Scholarship Fund, which would provide academic funding to students currently attending Lee's school. It's an attempt by an ephemeral community to make a lasting impact. Or as White told me, "There was an outcry from people that wanted to do something positive — people wanted to counteract the distastefulness of consuming other people's tragedies for their own entertainment." To date, the fund has drawn just $3,200 in donations, or 12 percent of its $25,000 goal.

For many, the intrigue was as much about Koenig's telling of the case as it was about the crime itself. Without the podcast, interest is bound to drop off. "I'm sure we'll see a lot of our regular users move on," White told me. "I could see people hanging out for about a week."

"No one was happy when Breaking Bad ended, but it just has to happen," White said. "Maybe it's a little distasteful to compare true crime to a piece of entertainment fiction. But podcasts, to be honest, are a combination of a news venue and an entertainment medium. And people consume this podcast in particular the same way they consume entertainment."

White said he didn't have very strong convictions about the nature of the case, and wasn't terribly invested in finding out whether Syed was innocent or guilty. While he likes the idea of a wrongfully convicted murderer finally finding justice, he's not certain whether that's the case here, or whether it was just a good narrative. Still, even before this season of Serial wrapped up, he was already looking forward to the next one.

"I'm a listener of a podcast," he told me. "That's all there is. I'm not an investigator. I'm not Sarah Koenig."