When Dexter first premiered on Showtime, it stunned audiences. This show revolved around a serial killer, Dexter, who you felt bad for. Rarely does a show star a character of such "evil" attributes and make them likable. But Showtime pulled it off. How? They had some help from the book series it was based on.

Darkly Dreaming Dexter is the 2004 novel by Jeff Lindsay. This book and the seven subsequent books star the lovable killer as he balances his job as a blood spatter analyst for Miami PD and his insatiable lust for killing. And even though the show scored eight amazing seasons on Showtime (with a less-than-stellar finale), it's easy to miss some of the nuances. Books, on the other hand, have the capacity to delve into details that are much harder to show on television. While the show and books have different story paths, the characterization of many characters is similar enough to glean info from.

RELATED: 10 Hilarious Dexter Memes Only True Fans Understand

With that note, here are 8 Things In The Show That Only Make Sense If You Read The Books.

Dexter's Bond With Debra

Dexter Debra

Debra and Dexter have a complex relationship as siblings. Debra wishes to be more open with Dexter, and Dexter is, well... Dexter — aloof and not quite human when it comes to emotions. But their relationship is still strong. In the books, Debra actually finds out about Dexter's dark secret relatively early on.

RELATED: Dexter: The Show VS The Book

Darkly Dreaming Dexter, the first book in the series, has Debra learning about her brother's killer nature. And in the end, she even chooses the hide this info from any prying eyes. Since Debra is on the police force in the books and series, this tidbit of information shows how deep the bond the siblings have.

Debra Always Knew Something Was Wrong

Debra and Dexter

As much as Debra jokes that Dexter is a sick dude, she also says those things to the rest of the guys in the Miami PD. Many of the men in this department who work with Dexter, such as Masuka, have a sick sense of humor and are a bit off. But it turns out that Debra's police senses were always tingling when it came to Dexter.

Perhaps it was the stark contrast in behavior between her and Dexter. Growing up together, Dexter was keen to hide his inner demons. But it turns out that he wasn't so good at hiding his sociopathic behavior. So despite Debra loving Dexter, she knew something was off about his demeanor.

Paul Bennett Might Have Abused the Kids As Well

Dexter and Rita with Baby

In Dexter, we see a locked up Paul Bennett, the father to Rita's two children. We learn that Paul abused Rita, both physically and emotionally. But it might get a little worse. While in the show we don't see Paul abuse his children, the books shed light on that subject. Paul was more messed up than we could have imagined, with Rita and the children on the receiving end of his abuse.

RELATED: 5 Best (& 5 Worst) Episodes Of Dexter (According To IMDb)

Perhaps Showtime didn't want to showcase a parent abusing his children. Despite being rated MA, many shows of that nature still shy away from certain acts. But this information does help us further understand the deranged nature of Paul Bennett and Dexter's disdain for him.

Dexter Used To Be More Detached

As we see from theeight  novels written by Jeff Lindsay, Dexter is a seemingly emotionless character who wants to feel something.  While Dexter is starting to learn how to fake feeling "human" on the television show, he eventually finds an inkling of emotions.

The character of Dexter in the novels is surely more detached. But the detailed nature of the books clears up his past as well. And while Dexter the show clearly delves into his past, the books further explain his emotional process. It turns out, he used to be even more detached from society. In fact, he rarely faked certain emotions because he had no idea how to until he was older.

Dexter's Dark Passenger Is Vocal

Dexter Dark Passenger

Dexter has a voice inside his head, ever since he saw his mother being sawed up and left in a shipping container.

In fact, traumatic events tend to leave imprints on us. It just happens that Dexter's voice is more like a ...passenger. It sits and watches Dexter's life and becomes very active in his... temptations. The killing kind.

Although we don't hear from the Dark Passenger in the show, Dexter hears it. He speaks of this "thing" in his head, but there is no voice in our ears narrating that aspect of the show. The less he kills in any given time, the more vocal this voice gets. And it is quite sinister. So despite the audience being unaware of how loud the Dark Passenger can be, it is still there, commanding Dexter to take more lives.

Rita's Kids Might Have Dark Passengers As Well

Dexter with Rita, Cody and Astor

The television show had Dexter falling in love with Rita, sort of. He starts to feel something, which is surely better than nothing. As for Rita's two children, it turns out they might have something psychologically wrong with them too. Whereas the television show has them be seemingly normal, there might be something dark hidden underneath.

In the book series, Dexter starts to teach them about Harry's Code, something that he never told anyone else. If the Showtime show would have persisted, there is a chance that Cody and Astor would have become Dexter's students.

How Dexter Actually Starts To Be His Dark Passenger

Despite years of being under the influence of the Dark Passenger, Dexter has come to a point of acceptance. But later in life, Dexter starts to fight against it.

When did this moment occur? At the birth of his child. While his child is named Lily Anne Morgan in the books, he actually has a son in the television show. Named Harry, after Dexter's father, we see something click in Dexter. He becomes more caring and wants to be there for his newborn. But what does that mean in terms of his Dark Passenger? That he finally is doubting and resisting it.

Although Dexter has become a killer at heart, the face of his own child in both book and show creates a glimmer of hope for him. And that glimmer is enough of a chance to start fighting against the Dark Passenger's temptations.

Dexter Enjoys Killing More Than He Lets On

Dexter

This one might seem a bit odd. Of course Dexter enjoys killing...you would think. But it turns out that the show winks at the idea that he feels forced to kill.

But this urge is created from the Dark Passenger. And it seethes into Dexter's mind. It gets to the point that Dexter relishes killing people, good or bad. Harry's Code is there so nothing bad happens to Dexter once Harry is dead. This is a two-part system. On one side, Dexter gets to generally keep on the gray-yet-good side of morality. On the other side, it keeps Dexter from killing those who don't "deserve" it. Dexter gets to exist in the world without getting innocent blood and his hands, and the streets of Miami are cleaned up a bit.

NEXT:  Dexter: 10 Storylines That Were Never Resolved