Divergent Allegiant two filmsEXCLUSIVE: Lionsgate/Summit will adapt Veronica Roth‘s Divergent novel trilogy into a total of not three, but four films starring Shailene Woodley as the dystopian sci-fi heroine Beatrice “Tris” Prior, Lionsgate Motion Picture Group Co-Chairmen Rob Friedman and Patrick Wachsberger revealed today. Following last month’s blockbuster hit Divergent and its planned 2015 sequel Insurgent, Allegiant – adapted from the third book in Roth’s bestselling YA book series – will be split into two separate films to conclude the franchise. Lionsgate had previously set Allegiant for a March 18, 2016 release. Allegiant Part 1 will keep that date, with Part 2 to follow on March 24, 2017. Both films will be produced separately.

Divergent has quickly made a box office star of Woodley, who will reprise her role in all three sequels as Tris, the 16-year-old girl who finds herself a target as one of few in her futuristic society who defy categorization into one of five personality-based factions. The first picture scored a $54.6M opening in March and has now racked up $117M domestic and $139M worldwide in three weeks of release. It’s still rolling out strong internationally and opens this weekend in France, Germany, Russia, Australia, Scandinavia, and other territories. Meanwhile sales of Roth’s novels have also enjoyed a bump from the film’s release, with boxed set and multi-book e-bundles jumping up 55 percent in sales last week and nearly 20 million copies sold worldwide.

Related: BOX OFFICE: ‘Divergent’ Opens At $54.6M

Splitting Roth’s final novel into two films isn’t a left field move for Lionsgate. Similar thinking first paid off for the company in a big way with Twilight Saga-ender Breaking Dawn. The Twilight Saga: Breaking Dawn Part II took in $829M in worldwide grosses alone and extended Summit’s vampire romance franchise into five films from author Stephenie Meyer’s original four novels. Likewise, the upcoming Hunger Games finale Mockingjay will be released in two parts on November 21, 2014 and November 20, 2015, respectively, squeezing an extra installment out of the final book in novelist Suzanne Collins’ YA series. Together the two film franchises have already grossed over $5 billion worldwide for Lionsgate/Summit, with last year’s Hunger Games: Catching Fire becoming the 10th highest grossing film of all time.

Divergent Allegiant“Veronica Roth brings her captivating story to a masterful conclusion in Allegiant, a rich, action-packed book with material that is ideally suited to two strong and fulfilling movies,” said Friedman and Wachsberger. “The storytelling arc and world of the characters lend themselves perfectly to two films, a storytelling strategy that has worked very well for us on the two Twilight Breaking Dawn films and about which we’re tremendously enthusiastic for the two upcoming Mockingjay films of The Hunger Games franchise.” Doug Wick and Lucy Fisher of Red Wagon Entertainment and Pouya Shabazian are producing the series.

The question is, where will Lionsgate split Allegiant‘s story? Conspiracies within the world of Divergent unfold further in sequel Insurgent, which begins filming next month under helmer Robert Schwentke, directing from an Akiva Goldsman rewrite of Brian Duffield’s draft. He got the gig when Lionsgate fast-tracked the sequel for a March 20, 2015 date while helmer Neil Burger was still in post-production on the first pic. Third book Allegiant is told from the perspectives of both Tris and fellow initiate Four, played in Divergent‘s film adaptation by Theo James, as the characters enter a dangerous new world they no longer recognize and new truths are revealed about the past and future.