Fans rejoiced when FOX announced the return of "Prison Break," but its plot had remained a mystery -- until now, as the network released its first full-length trailer.

Based on earlier reports, the series will address the alleged death of Michael Scofield (Wentworth Miller) during the fourth season finale in 2009. This was to help his brother, Lincoln Burrows (Dominic Purcell), and his wife, Sara Tancredi (Sarah Wayne Callies), escape prison.

But it can be seen in the new trailer that Michael is still alive, but both Lincoln and Sara have no idea about it.

In the beginning of the trailer, Michael's son, who has the same name as him, asks Sara to describe what his "real father" was like.

"He was like a storm appearing suddenly out of a clear blue sky, and then disappeared just as quickly," Sara replies. The little boy answers her, saying: "But storms can come back, can't they?"

It seems like little Michael can predict the future, as the trailer shows one of the brothers' former friends in the prison visiting Lincoln in his home, saying that Michael is alive but incarcerated in a foreign prison.

Lincoln is skeptical about the information at first, but he decides to tell Sara about it. Both of them have no idea if they will believe the news, but Sara tells her former brother-in-law, "I know you want it to be true—I want it to be true."

This prompts Lincoln to pack his bags and travel across the world to see for himself if Michael is really alive. When he comes face to face with his brother, Lincoln decides that he will do whatever it takes to get him out just like what Michael did for him in the past. But the escape will not be an easy feat, since a major citywide blackout will be necessary to make sure that their plan will be a success.

By the end of the trailer, Lincoln and Michael have a dramatic reunion. But does it mean that they could successfully return home to Sara without other complications?

"Prison Break" season 5 is expected to premiere sometime in 2017.