How Unfinished Movie Franchises Were Supposed To Go, According To The Books

Along with Harry Potter and Twilight, the Percy Jackson series was one of the biggest YA fantasy hits of the 2000s, but even its massive popularity didn't turn the movie series as successful as it could've been. Of the five books in the original series, only two were made into movies: Percy Jackson: The Lightning Thief and its subsequent sequel Sea of Monsters. The second film cuts the saga short with son-of-Poseidon Percy (Logan Lerman) and his pals back at Camp Half-Blood after having successfully retrieved the legendary Golden Fleece, defeated the evil Luke Castellan and his Titan master, Kronos, and resurrected the long-lost daughter of Zeus, Thalia. The film teases a continuing story by revealing Percy and Thalia are the two possible subjects of a “Great Prophecy” detailing that a child of the eldest three gods will be responsible for either saving or destroying Mt. Olympus. However, the prophecy was never resolved on the big screen.

The original Percy Jackson series had three more novels, with The Titan's Curse and The Battle of the Labyrinth next up. The Great Prophecy finally resolves in the fifth book, The Last Olympian. In this book, Percy gathers an army of demigod allies and mythical creatures to defend Mt. Olympus (located at New York City's Empire State Building) against the renewed Luke, Kronos, and an army of enraged Titans. Percy's brave actions bring the Great Prophecy to pass as he protects Olympus from the Titans.

The Divergent series rode the wave success of YA dystopian novels led by The Hunger Games before it, though this film franchise based on Veronica Roth's trilogy couldn't match that success. Set in a post-apocalyptic version of Chicago divided into five factions based on what virtue the people prize most - Abnegation, Candor, Amity, Erudite, and Dauntless - the the three films that starred Shailene Woodley, Theo James, and Miles Teller all enjoyed solid-to-modest box-office success. Critical reactions were mixed to begin with, but by the time Allegiant: Part 1 was released, the response from critics was dismal, leading to the cancelation of the fourth film that was planned to adapt the second half of the final book.

With the prospective Part 2 never making it to the big screen, the Allegiant novel is now the only place audiences can find the resolution. Escaping the bounds of Chicago, Tris discovers that their city was actually constructed as an experiment to increase the population of “divergent” individuals like Tris, who are actually normal humans, while the rest of the city's population are genetically damaged from a failed attempt at gene manipulation that caused a war in the past. Tris then learns that the creator of the experiment plans to unleash a memory-erasing serum on the population in order to quell rebellion and keep the experiment running. Ultimately, Tris sacrifices her own life to stop the memory-wipe and free the people of Chicago, perfectly ending her series-long struggle between her selfless upbringing with Abnegation and the bravery she embraced with Dauntless.

C.S. Lewis's classic series The Chronicles of Narnia, which follows the Pevensie children as they explore the magical land accessible through a wardrobe in their country home, saw three successful movie adaptations from 2005 to 2010. While the film series earned over a billion dollars in revenue overall, due to diminishing returns, the franchise's third film, The Voyage of the Dawn Treader was to be its last. Many fans were heartbroken at the lack of continuation, since the Narnia series is comprised of a complete arc of seven novels, meaning over half the series was left unadapted. 

The fourth book, The Silver Chair, picks up with reformed bully Eustace Scrubb, the Pevensies's cousin who joined them in Narnia in Voyage of the Dawn Treader, returning to Narnia a year later. With fifty years having passed inside Narnia, Eustace and his schoolmate Jill inevitably are sent on a mission by the god-like lion Aslan to recover the now-elderly King Caspian’s missing son, Prince Rillian, in order to secure continued peace in Narnia. Eustace and Jill succeed in recovering a kidnapped Rillian, just in time to reunite him with their old friend (and his father), King Caspian for a moment of joy. Caspian dies shortly thereafter, to Eustace and Jill’s heartbreak. Aslan responds by resurrecting a young version of Caspian for a short period of time, and allowing him to briefly return to London with Eustace and Jill to help them defeat their real-world bullies.

The Inheritance Cycle was a fierce phenomenon in the 2000s YA literature market, written by Christopher Paolini, only 19 when he published the first book of the series, Eragon. The 2006 movie adaptation keeps the same fantasy adventure, following a farm boy named Eragon (Ed Speelers) who discovers and raises a dragon, Saphira. Together, they learn the ways of the ancient Dragon Riders and battle the evil King Galbatorix (John Malkovich) under the guidance of a group of rebels called the Varden. Against all odds, coming from the popular book series, the film was derided by critics, and fans of the novel were disappointed by several changes to the story. As a result, none of the later books were adapted. 

Had the story continued on screen, Eragon’s sequel novel Eldest details Eragon and Saphira's journey into the land of the Elves as they continue their training and support the rebellion with the Varden. The whole affair culminates in a massive showdown between the warring factions, and the ultimate reveal that Eragon’s old pal-turned-rival Murtagh is his half-brother, sharing the same mother, Selena. The third novel, Brisingr, further reveals that Eragon's real father was his first mentor, Brom.

The Maze Runner movie and its subsequent sequels, based on books by James Dashner, star Dylan O'Brien as Thomas, who wakes up without his memories at the center of a sprawling maze, where teens form a society and try to find a way to escape the walls around them. As the group explore the dangerous maze, they slowly learn about the organization called WCKD, which trapped the kids there as part of an experiment. This YA franchise was a rarity, in that every novel in the main trilogy was successfully adapted into a movie, completing the main arc. Despite that success, the two prequel novels, The Kill Order and The Fever Code, have not been adapted. 

In The Kill Order and The Fever Code, Dashner explores the origins of WCKD, the World Catastrophe Killzone Department, which begins in response to a solar flare causing a deadly virus that devastated the world's population. Thomas is born immune to the virus and taken away from his mother at a young age and raised along with Theresa and other immune children at WCKD's facility. There, Thomas is trained by scientists while prevented from exploring the apocalyptic world outside, and he even helps design the maze that kept the others from escaping. Feeling bad, Thomas hatches a plan to enter the maze and help the others escape, but a betrayal results in his memory getting wiped as he enters, beginning the events of The Maze Runner.

Adapted from the first book of the Lorien Legacies series by Pittiacus Lore, I Am Number Four follows a group of nine alien children called the Garde who take refuge on Earth, blending in with humans, to hide from the evil Mogadorians who hunt them down according to their birth order. Number Four AKA John Smith (Alex Pettyfer) works with his human friends, as well as one of his siblings, Number Six, to escape from the first wave of Mogadorians who are hunting him after killing the first three of his siblings. The movie ends with Four, Six, their human pal Sam, and Four's shapeshifting pet Chimera Bernie driving into the sunset with a promise to defend their new home planet. Though the sci-fi adaptation managed a modest profit on a reasonable budget, critics were less than kind, and fan enthusiasm petered out relatively quickly.

The Lorien Legacies series continues for a total of six novels; if the film series had continued, it would follow the second book, The Power of Six. The second book picks up with the gang as they continue evading enemy alien battalions and searching for the remaining members of the Garde. They learn that Sam's father, Malcolm Goode, was aware of the aliens and had helped Four settle on Earth years ago. After Four and Sam are captured by the FBI, Six appears and rescues them - beginning a romantic tease between her and Four, despite Four also having feelings for his human friend Sarah.