"Divergent": Watch the final trailer

The final trailer for "Divergent" arrived online Tuesday, and it packs a little history lesson for those not familiar with the bestselling book it's based on.

As Beatrice "Tris" Prior (Shailene Woodley) explains in a voiceover, "One hundred years ago, after the war, our founders created a system they believed would create lasting peace: They divided society into five factions."

"Everyone is tested to determine who we are, and where we belong," she adds.

Of course, as fans of the book know, Tris discovers she’s "divergent" -- meaning she doesn't conform to any one of those factions -- must then find out why that’s considered dangerous.

Kate Winslet, Theo James, Ashley Judd, Zoe Kravitz, Miles Teller, Ansel Elgort (who co-stars with Woodley in the upcoming "The Fault in Our Stars") and Maggie Q also star in "Divergent," which opens in theaters on March 21. Watch the trailer below: