Ansel Elgort and Shailene Woodley must currently have a good thing going on the set of "Divergent," as once that gig wraps they'll be teaming up again for another YA (yet decidedly more real-world) adaptation, "The Fault in Our Stars."

"Fault" is based on the novel by John Green that chronicles the tragic love story of Gus and Hazel, two teenagers who meet in a cancer support group. "Their ensuing love story is as real as it is doomed, and the gut-busting laughs that come early in the novel make the luminous final pages all the more heartbreaking," according to the rave review at Entertainment Weekly.

Woodley beat over 250 candidates for the role of Hazel Grace Lancaster this past March, with director Josh Boone claiming that "it wasn't until Shailene stepped in front of the camera that I truly saw Hazel for the first time. It was like lightning striking. I can't wait for the rest of the world to see what I have."

Meanwhile, Elgort, who plays Woodley's brother in "Divergent," has been cast as Augustus 'Gus' Waters ... and novelist John Green couldn't be happier.

“Ansel is whip-smart and uber-charismatic and everything I dreamed for Augustus Waters," Green told Inside Movies in an exclusive statement. "I am by nature a cautious pessimist, but I’ll just say it: Now that we have Shailene and Ansel, I am completely, unreservedly psyched about this movie."

Production on "The Fault in Our Stars" will commence once Woodley and Elgort wrap their respective roles as Beatrice 'Tris' Prior and Caleb Prior in "Divergent." It will certainly be interesting to see the duo go from siblings to sweethearts over the course of two consecutive film projects ... and probably a little weird, too.

Meanwhile, Ansel Elgort will next be seen as dreamboat Tommy Ross in the "Carrie" remake, opening Oct. 18, and Shailene Woodley will next be seen in "The Spectacular Now," opening Aug. 2. Woodley also recently wrapped her role as Mary Jane Watson in "The Amazing Spider-Man 2," which opens May 2, 2014.