Last year, forty million people downloaded the first season of Serial, making it the most popular podcast ever made. People all across the world were listening and relistening to the gripping story told in twelve episodes.

The first season was so popular that Serial told eager fans that they were hard at work on second season. There was an element of mystery and a great deal of speculation about the topic of season two. Would it be just a continuation of the first season? Would it be about another murder case? Rumors flew around the Internet as fast as people could type. No one knew what to believe or what to expect.

Then on Dec. 10, 2015, the eagerly anticipating first episode of the second season was finally released. It was quite sudden; there was no warning or notification telling the fans that season 2 was to be released on that day. The first episode is called DUSTWUN. The topic covered a soldier named Bowe Bergdhal.

The episodes begins with Sarah Koenig describing a video which shows the rescue of a Bowe Bergdhal. Bergdhal was a U.S. soldier who was captured by the Taliban and held for five years. Normally, the return of a U.S. soldier after five years of captivity would be cause for celebration. However, the circumstances of his capture were unusual. Bergdhal was not captured under the orders of his supervisor. He deserted his post.

That begs the question: why did Bowe desert? That question is the topic of the first episode of Serial season two. Episode two discusses the rescue of Bergdhal and why it took so long. The third episode goes into more detail about his desert, where he went, when he was captured. The most recent episode, episode four, describes his capture and what happened to him in those five years that he was held prisoner.

With each episode, more questions are forming than are being answered. And, slowly but surely, a story is being created about what happened to Bowe Bergdhal.

Serial remains the most popular podcast ever created. Every Thursday, a new episode is released to the millions of listeners, eager to know what happens next.

The first season was about a murder committed seventeen years ago. On January 13, 1999, a high school senior girl named Hae Min Lee went missing. Her body was found a month later, buried in the woods. Her ex-boyfriend, Adnan Syed, was arrested three weeks later and charged with first-degree murder. He’s been in jail ever since.

However, the podcast wasn’t just about the murder. The story told in Serial is about the investigation, the trial, and whether or not he did it. Adnan has never deviated from his story, and which is that he had absolutely nothing to do with Hae’s death. The more the listeners of Serial learn about it, the more mystifying it becomes. The timeline for the murder is inaccurate, the witnesses are unreliable, and Adnan’s lawyer disregarded an alibi witness. It’s an intriguing story and the number of people listening to the podcast grew at an alarming rate with each new episode. The final installment was released in December of last year.