"Serial," the mega-hit podcast  that was downloaded over 100 million times and earned a Peabody award, is finally back for a second season. After the first series explored the story of Adnan Syed and the murder of Hae Min Lee, host Sarah Koenig and her crew are back to investigate an all-new story, this time focusing on the tale of Army Sgt. Bowe Bergdahl.

The first season of "Serial" was all about an unknown murder case, but the second season has changed its tune entirely. The case of Bergdahl is one of the most controversial and well-known cases of the past couple of years.

Bergdahl disappeared from his post in eastern Afghanistan under "mysterious circumstances" back in 2009, as HNGN previously reported. He was rescued in May 2014 by a U.S. Special Operations team in Afghanistan after he was held prisoner by the Taliban for five years. He was only set free when the U.S. negotiated his release and was forced to free five Taliban detainees from Guantánamo Bay. When Bergdahl arrived back stateside, public opinion of him soon changed and he was labeled a deserter by his fell soldiers.

In the premiere episode of "Serial" called "DUSTWUN," Bergdahl shares his side of the story for the first time and recounts what happened that day he left his post.

"I'm going, 'Good grief, I'm in over my head,'" Bergdahl said in the first episode of the podcast.

"Suddenly, it really starts to sink in that I really did something bad," he continued. "Or, not bad, but I really did something serious."

"Unlike our story in Season One, this one extends far out into the world. It reaches into swaths of the military, the peace talks to end the war, attempts to rescue other hostages, our Guantanamo policy," Koenig wrote on the podcast's website. "What Bergdahl did made me wrestle with things I'd thought I more or less understood, but really didn't: what it means to be loyal, to be resilient, to be used, to be punished."

Bergdahl was charged with desertion and misbehavior before the enemy, a charge that carries up to life in prison, but he is currently waiting to see if his case will go in front of a court-martial, which would lessen the charges to a misdemeanor, according to NBC News.

You can listen to the first episode of "Serial" here.