(CBS Local)– On Sunday, Showtime will release part one of a four part docu-series called “Enemies: The President, Justice & The FBI.”

The series is inspired by the book “Enemies: The FBI,” written by Pulitzer-Prize winning author Tim Weiner.  With executive producer and Oscar winner Alex Gibney guiding its vision, the series dives into the history of presidents from President Richard Nixon to President Donald Trump and their battles with law enforcement. The series culminates with a finale of President Donald Trump firing former FBI Director James Comey.

Weiner recently dropped by the CBS Local Studios to discuss the show, along with his thoughts on the ongoing saga with President Trump and Robert Mueller.

“The FBI is the most powerful force and I think the only force that is able to go up against the president when he breaks the law or bends the Constitution,” says Weiner. “In the spring of last year, the series came into place when President Trump fired Director Comey. We knew we were in the midst of an epic confrontation between the president and the FBI.”

While Weiner says the president’s lawyers fear he would perjure himself if he ever sat down with Mueller, the Pulitzer-Prize winner believes there is a responsibility from Trump and his lawyers to answer the questions they’re presented.

“The President and his lawyers are struggling to answer Robert Mueller’s questions about whether he fired Jim Comey with a corrupt intent to obstruct the investigation that the FBI was conducting into the Russia hacks,” said Weiner. “It had been a counter-intelligence investigation about the attack on our election. When the President fired Jim Comey, it became a criminal investigation.”

While the firing of former attorney general Jeff Sessions topped the headlines recently, Weiner wants to remind everyone that President Trump doesn’t directly have the power to fire Mueller.

“The President can’t fire Mueller. Under the law, he has to get someone at the Justice Department to do it,” says Weiner. “If this guy Matthew Whitaker tries to fire Mueller, Mueller’s grand jury is going to put him in their crosshairs on obstruction. Bottom line, Trump can’t fire the FBI.”

Speaking of Mueller, Weiner had the opportunity to spend a few hours with the former FBI director two years ago. The author says the leader of the investigation into Trump and his affairs is one of the most important people in 21st century American history.

“I interviewed Mueller at an international security and law enforcement conference two years ago and we hung out afterward,” says Weiner. “This is a guy who represents an old school public service. He came out of Princeton and signed up to join the Marines at the height of the Vietnam War. If you are a lieutenant as Mueller was, and you order your men to go up the hill, you go up the hill first. Mueller has spent his life working for the greater good of the United States. There are very few people like him in the government of the United States today. He will not bend or break under political pressure.”

There is certainly a lot to focus on with this story in the present, but Weiner is already starting to think about the future. The author believes that things will ultimately end badly for President Trump once he becomes a citizen again.

“Some day, President Trump will be citizen Trump and he will not be protected by the immunity granted to presidents from indictment,” says Weiner. “He will be, I predict, in a world of pain.”

Watch “Enemies: The President, Justice & FBI” Sunday, Nov 18 at 8pm EST on Showtime.