When Amazon bought the TV rights to The Lord of the Rings universe in November, fans were surprised. Christopher Tolkien, J.R.R. Tolkien’s youngest son and literary executor, famously despised the commercial incarnations of his father’s work and refused to sell more access to the property. But all became clear within days, when it was revealed that 93-year-old Christopher had resigned as executor, opening up the Tolkien universe to the highest bidder. In this case, it was Amazon, which offered a whopping $250 million for a multi-season deal.

It’s easy to understand what Amazon sees in Tolkien’s vast world. It provides a chance to compete with fantasy epics like Game of Thrones and to milk Tolkien IP to create a small-screen franchise of its own. This is probably why the company hired J.D. Payne and Patrick McKay as showrunners. The Verge notes that the two-man writing team has experience working inside existing franchises, with credits on Star Trek Beyond and the upcoming Godzilla vs. Kong and untitled Star Trek sequel.

However, Amazon should note that Middle Earth is not as flexible a universe as that of Star Wars or Star Trek. Tolkien’s world was underpinned by a strong, coherent worldview—if you get that wrong, the story will lose the mythic power that made it popular in the first place.

In a 10,000-word letter laying out “a brief sketch” of his world for a publisher, Tolkien wrote that his world was “main concerned with” three things: “Fall, Mortality, and the Machine.” Reportedly , Amazon is planning for the first of five series to be an original story focusing on a young Aragorn. The peril of crafting entirely new stories within the Tolkien legendarium is that modern attitudes often conflict quite strongly with Tolkien’s tragic but hopeful vision. For instance, Star Trek’s optimistic, humanistic utopia could not be more different from Middle Earth’s melancholy, eucatastrophic setting.

Loss permeates Middle Earth. The Lord of the Rings has a happy ending, but its victory is tenuous and expected to be short-lived. The good guys lose—protagonist Frodo is corrupted—and victory is achieved only through a Deus ex machina when a villain slips on a rock. “Together through ages of the world we have fought the long defeat,” says immortal Galadriel of herself and her husband.

The Lord of the Rings itself is about a journey to lose an item—the inversion of the traditional fantasy quest to acquire treasure. Frodo gives up a comfortable life in the Shire to bear the ring to Mordor. The book ends with the Shire ravaged by war and a wounded, traumatized Frodo leaving Middle Earth forever. This progress echoes the experience of Tolkien himself, who came home from the Great War having lost all but one of his closest friends during the Battle of the Somme. The war shattered Europe, and in similar fashion, Tolkien’s Middle Earth is also a world mourning a past age, facing its own mortality.

The desire to defeat mortality and avoid decay at any cost is the primary corrupting motivation for Tolkien’s villains. These villains “rebel against the laws of the Creator” and have “a desire for Power” to dominate and “bulldoz[e] the real world and coerc[e] other wills,” Tolkien wrote.

Their perverted desires open the door for their fall. The siren song of possessive, domineering power over mortality is tempting to all of Tolkien’s characters, from Gandalf, who would use the power for “strength to do good,” to the Elves, who use it to preserve their beautiful, immortal havens, to men, who wish to build and defend their own kingdoms.

Machines are the obvious physical manifestation of this mindset: a wholly controllable object, created by the machinist and totally enslaved to his will. By expanding this mindset to organic life, people become cruel, false gods, seeking complete control of things that they did not create and do not own. “He that breaks a thing to find out what it is has left the path of wisdom,” observes the wizard Gandalf, pointing out that such extreme physical reductionism loses something essential, something greater than the sum of the dissected parts.

Mortality, Fall, and the Machine: These themes, which are mere summaries of the vast complexity and richness of Tolkien’s vision, aren’t easy to translate faithfully to the screen, but without them—without the strong anchor of Tolkien’s worldview—the stories will be missing the strong elegiac resonance of Middle Earth.

Peter Jackson’s Hobbit trilogy made this mistake. The bombastic, colorful blockbusters relied heavily on intertextual references to iconic Lord of the Rings moments, from a pointless subplot introducing a character with no relevance to the plot of The Hobbit (the Necromancer), to randomly name-dropping characters like Aragorn. The Hobbit knew the notes of Tolkien’s world but not the tune. As a result, the story turns Tolkien’s beloved children’s story into a clowning, brainless blockbuster. Perhaps the best example of how badly it read the spirit of the original work is that the extended edition of one of the films ended up initially being rated R.

By contrast, Jackson’s Lord of the Rings trilogy caught, though imperfectly, the broad strokes of Tolkien’s ideas. The ring’s ability to stave off mortality and dominate creation is well-established in the trilogy. The story’s bittersweet ending was diluted by the removal of the Scouring of the Shire scene, but remains in Frodo’s gradual withdrawing from Middle Earth (it’s why the many endings of Return of the King are justified ).

Sam Gamgee’s speech in The Two Towers film describing his hope for this beaten-up, broken-down world echoes Tolkien’s own belief, drawn from a passage of Chesterton , that despite the sadness of the Earth, “when you do love a thing, its gladness is a reason for loving it, and its sadness a reason for loving it more.”

Or as Sam puts it, “There’s some good in this world, Mr. Frodo. And it’s worth fighting for.”

Tolkien’s universe is full of opportunity for expansion, and he wasn’t opposed to the idea (in the same letter to his publisher, he spitballed about creating a myth so expansive that a whole culture could add to it). However, if Amazon wants to build an expanded universe, it will have to understand the universe it’s expanding.

With Amazon’s emphasis on new stories and addicting storylines, and with a successful but dumbed-down film franchise looming in audience’s memory, it could be easy to neglect the rich literary milieu to which it has gained the rights and just focus on crowd-pleasing spectacle. That would be a shame and a waste. For the story to ring true, Amazon must capture not just the mythos but the ethos of Tolkien’s world.