Star Wars is one of the most popular science fiction series ever made. With the completion of the Skywalker Saga, Disney has capitalized on this fame and popularity, taking from some of the best of the material in the Expanded Universe while introducing new characters and plot lines for a whole new audience.

Whatever audiences think about the most recent films, it is clear Disney intends to keep making more. It is only natural that the Star Wars books will continue to inspire future movies and TV shows, but many of those books have content that is a bit mature for the Disney brand. Here are ten things from the Star Wars books that are too mature for the movies.

Mental Illness

In the fan-favorite novel Heir to the Empire by writer Timothy Zahn, the character of Joruus C’baoth is first introduced as an evil manipulative Jedi Master recruited to stop Luke. In truth, this version of Joruus C’baoth is a clone of the original Jedi Master. The cloning process and C’baoth’s force abilities did not mix well and the clone quickly became insane (though it should be noted that the original C’baoth, featured in Zahn’s novel Outbound Flight, also demonstrated narcissism and obsessive-compulsive tendencies).

Zahn does a lot right in his books, but making a crazy evil wizard is not exactly a nuanced take on the difficulties presented by mental illness. The only mental health issues the movies are ever likely to show are Finn’s struggles with PTSD.

LGBTQ+ Representation

First, let it be noted that there is nothing inherently mature about LGBTQ+ characters being represented - though it does take maturity to acknowledge that such representation matters. While The Rise of Skywalker had a same-sex kiss, this was Disney making a token nod toward representation (and one easily cut by censors in less tolerant countries).

One of the best characters in any Star Wars book is the roguish archaeologist Doctor Aphra, who first appeared in Marvel’s Darth Vader comic and was created by writer Kieron Gillen before getting her own series. On her adventures, Aphra has left many women angry at her across the galaxy after bad break-ups. Before the new canon, it seems that only Mandalorians were known to have same-sex marriage, as seen with the bounty hunter Goran Beviin and his husband Medrit Vasur in the novel Legacy of the Force: Sacrifice.

Organized Crime

There is definitely organized crime in Star Wars. The Hutts are the easiest example to point to while Solo introduced moviegoers to the Crimson Dawn. However, the inner workings of these groups are seldom seen.

In the novel Shadows of the Empire, the crime boss Xizor is hired by Palpatine as Xizor’s cartel, the Black Sun, has the resources to transport goods for the Empire as they rebuild the Death Star. This is one of several books to look at the inner workings of organized crime as more than just a nebulous group of baddies for the heroes to oppose.

Racism

In the opening crawl of the original Star Wars, audiences learn that the Empire is evil. Well, as they had not yet resorted to their anti-Alderaan campaign of planetary annihilation, this begs the question of what was so evil about them. One easy answer is that the Empire is racist. Really really racist.

Throughout multiple novels in the Expanded Universe, it is made clear that the Empire embraces policies of human supremacy. Unfortunately, Disney seems unlikely to tackle any potentially heated topic in fear of alienating someone.

Colonialism

George Lucas always intended for Star Wars to be political. The Empire’s uniforms are based on Nazi attire, while there are clear indictments of the War in Vietnam manifested through the Battle of Endor. The Thrawn Trilogy took these political themes a bit further by introducing the Noghri, a colonized alien people whose lives were upended after Darth Vader made a pact with them in exchange for granting them the technology to feed themselves after poisoning the planet’s atmosphere so indigenous plant-life would die without Imperial aid.

Showing actual colonialism on-screen seems like something too nuanced for the current version of Star Wars. Then again, as the Noghri are portrayed in a manner inspired by racist archetypes of the noble savage, they may not be well suited for a movie adaptation.

Eugenics

Controlled breeding experiments are one of the darker tropes in science fiction. Most stories combine actual genetic science with fringe theories about social Darwinism and really problematic ideas. One way eugenics came into play in Star Wars was in the Kaminoan society, as the Kaminoans engaged in genetic breeding programs to optimize their chances of survival.

While such a dark revelation would actually be perfect for an on-screen adaptation, it is unlikely that the Kaminoans will appear much more than they have.

Biological Warfare

There is a lot of biological warfare in the Star Wars Universe. One bioweapon is known as the Emperor’s Plague, a synthesized disease that only killed humans, seen in the Young Jedi Knights series. A similar engineered plague that only targeted non-human aliens is the Krytos virus first seen in X-Wing: Rogue Squadron. Some biological weapons are more creative, like the one that crippled the Noghri’s food supply, forcing them to choose between starvation or enslaving themselves to the Empire.

While the Clone Wars TV series has a story that references a biological attack, actual portrayals of the devastation created by a weaponized disease are not something audiences will be able to watch while continuing to keep down their popcorn.

Redemption

This is not an example of something taboo, but rather something that requires exploring actual moral complexity. In the nine main Star Wars films, two major characters fall to the dark side and are then redeemed: Anakin Skywalker and Kylo Ren. Both characters have just enough screen time to prove they are good before immediately dying in an act of self-sacrifice. Neither one has to live with the weight of their past misdeeds as they struggle to live a good life. The other redeemed hero, Han Solo, was never a bad guy, just a bit of a scoundrel.

In the Star Wars books, some of the most compelling characters include Mara Jade and Guri, both murderous ex-villains who seek redemption and are given a chance to receive it.

Abandoning Refugees

The Battle of Jabiim is considered one of the darkest events of the Clone Wars. The Republic forces on Jabiim are completely overrun and many Jedi are killed in this conflict. When the Republic armies finally retreat from the planet, they abandon the Jabiimi people they’d allied with and sworn to protect, consigning them to death.

This is a gut-wrenching defeat and is the sort of scene one does not easily forget. Unfortunately, showing something like this complicates the morality tale of good versus evil, so it is unlikely to appear in the films.

Genocide

The Death Star can destroy a planet with a single blast from its weapons system. The same can be said of the Starkiller Base in The Force Awakens, albeit doing so multiple times over. It is harrowing to watch a planet destroyed, but such a thing is seen from a distance.

There are several successful or attempted genocides in Star Wars, but the example of the Noghri is one of the most well-known, as they were given a choice between annihilation through starvation or enslavement that would wipe out their culture (which is also a part of genocide). The Mandalorians and the Empire have committed a number of other notable genocides in the Legends books. That’s not exactly the sort of thing shown in children’s movies.