In just two weeks, the highly anticipated film adaptation of Veronica Roth’s wildly popular YA series Divergent will hit the big screen. But before you head to see it in theaters, you may want to brush up on who’s who in this large ensemble cast. Sure, there are plenty of well known actors in it, including Shailene Woodley, who plays the film’s heroine, Tris Prior. And there’s also other big names, such as Oscar-winner Kate Winslet, Ashely Judd, and Mr. President Fitzgerald Tony Goldwyn.

But the film is also filled with a slew of rising stars, many of whom aren’t yet recognizable, but will be soon enough! If you’ve watched the trailer and still can’t place where you’ve spotted the actors, we did some research to jog your memory. (For example, Four, played by Theo James, was the doomed Mr. Pamuk from Downton Abbey, and he also was featured alongside Woodley in our March issue, plus Lenny Kravtiz’s daughter, Zoe, has a lead role as one of the transfer initiates, Christina.)

For a full Divergent cast lesson before the film opens March 21, click through the gallery now.