The series "The Event" is an emotional and thrilling mystery that sets up several individuals, from all walks of life, in a collision course with a worldwide conspiracy that could change the fate of the world.

The series focuses on Sean Walker (Jason Ritter), a recent video game programmer graduate of MIT, who begins to uncover a U.S. coverup as he searches for his missing girlfriend, Leila Buchanan (Sarah Roemer).

Seans investigation, unknowingly, begins to impact the lives of several strangers, including President Elias Martinez (Blair Underwood), First Lady Christina Martinez (Lisa Vidal), CIA Agent Simon Lee (Ian Anthony Dale), and the leader of a mysterious group of detainees, Sophia Maguire (Laura Innes). Also deeply affected by his daughter's disappearance is Michael Buchanan (Scott Patterson), who appears to have taken matters into his own hands to effectuate the return of his daughter.

As Sean's search expands and deepens, whether it reveals that the detainees are behind Leila's disappearance or if there is another party maneuvering everyone as if they were pawns in a global game, remains to be seen. But it is not who has Leila and why that is the biggest mystery; instead, all anyone is going to be asking is: what is the event? What is everyone so deathly afraid of and desperate to hide?

While the first episode starts slow and goes through a series of reverse time-jumps in order to explain the sequence of events that led up to Leila's disappearance, the last five minutes of the episode makes the labyrinthine journey worthwhile. A room of 2,500 fans gasped collectively as those final moments unfolded at San Diego Comic-Con, and there were cheers in the end. So it is worth investing an hour of your time to see if "The Event" will capture your attention as resoundingly -- and if it will hook you the way it did the Comic-Con fans.

Either way, "The Event" should prove to be a highly-entertaining and thought-provoking new series to watch this fall. It just requires a little patience and commitment to see how the complex mystery unfolds and how each seeming disparate character becomes intertwined.

Find out what happened to Leila Buchanan, why the government is hiding thousands of mysterious detainees, and what exactly the event is.

Make a date with The Event which premieres Sept. 20 at 9 p.m. ET on NBC.