For the fourth time, Joe Goldberg, played by the charming Penn Badgley, is back on his BS in Netflix’s hit psychological thriller, You. The show about a man that takes the phrase “I would do anything for love” to a new, twisted level premiered back in 2018 and has been stalking viewers’ hearts ever since. But some fans might not know that the show is based on a book series by Caroline Kepnes. While the TV series remains a relatively faithful adaptation, the show’s writers seem to stray more from the books with each new season. These differences, however, are the most significant reason fans should take a page out of Joe’s book (literally) and check out the novels.

One of You’s biggest draws is that it gives the audience a front-row seat to Joe’s thoughts. Witty and often brutally honest, Joe thinks things we wish we could say. Mostly, he doesn’t actually say them but covers his thoughts with what he says to manipulate a situation or person into getting what he wants. This is usually affection or a way to cover his tracks and maintain the illusion of an innocent man.

Only some things translate well from book to screen. The basis of screen storytelling is to show, not tell; however, in novels, the story is played out through a character’s thoughts. Due to this fundamental rule, Joe’s thoughts on TV are more elaborate in the novel and thus make him much darker. It’s incredibly similar to another fictional serial killer, Dexter Morgan, who is also darker in the books.

In the books, Kepnes doesn’t hold back on Joe’s incredibly violent and perverse thoughts. Another thing that makes Book Joe darker is the absence of the charismatic performance from Badgley. Both versions of the character share the delusion that their actions are justified, but TV Joe is more remorseful than his novel counterpart and has a stronger desire for change. Joe’s only kill so far in Season 4, for example, was in self-defense. If Book Joe and TV Joe met, they’d probably loathe each other.

Another thing that makes TV Joe not as dark is his stronger hero complex. Season 2 sees him feel the need to look out for a 15-year-old girl named Ellie, played by Wednesday star Jenna Ortega. Similarly, in Season 1, Joe rescues his neighbor Paco (Luca Padovan) from his abusive stepfather. These kids aren’t in the novels but exist in the show to make Joe more likable. Furthermore, Joe’s backstory on the show about being abused by his mentor Mr. Mooney is missing, taking away more sympathy for the character in the books.

What would Love be without her wild and problematic twin brother? Forty Quinn, brought wonderfully to life by James Scully, had many fans crying, “He deserved better!” after the character’s demise. However, that might not be the case for fans of the book. From disappearing on benders for long extended periods with no communication with his grieving family to ruining a newlywed couple’s wedding night with an indecent proposal, Book Forty is just the worst. The worst thing Book Forty does is trick Joe into believing they are co-writers on his screenplays, only to double-cross Joe, selling the scripts to film producer Megan Ellison as his own, striking a multi-picture deal.

One huge difference with the twins comes from a story Love tells Joe in the series about Forty being abused by a babysitter they had, leading to her first kill to protect her brother. In the book, she tells Joe about a puppy they had when they were kids that Forty killed. It’s Forty who has murder tendencies, not Love. In fact, Book Love is not a killer at all! Gasp!

In the novel, Love might not be a killer, but she does accept Joe for who he truly is when he confesses everything to her. She even returns to Peach’s home to retreive the mug of urine Joe left behind in the first book as a sign of loyalty. And just like in the series, Love reveals she is pregnant, but just when it seems like the happy ending, Joe is arrested for the murders of Guinevere Beck and Peach Salinger!

Love is a main staple of Season 3, but in the third novel, Love is only mentioned when Joe sees her and his son on Instagram. One day she calls him with the promise that he can finally meet his son. When Joe gets there, however, Love pulls a gun on him, demanding he says he loves her. When he refuses, she shoots him in the head before turning the gun on herself, dying after attempting to kill Joe, just like her on-screen version. Somehow, Joe survives, but never gets to meet his son.

In the third book, a private investigator hired by the Quinns named Oliver catches Joe disposing of a body and leverages the money that the Quinns paid Joe to blackmail him into continuous payments to keep quiet. In Season 4, Part 1, Joe meets Elliot, a man sent by Love’s father to kill him. Just like Oliver, he extorts Joe for money he got from the Quinns in exchange for Joe’s life.

It’s clear that the books and the show have split into entirely separate storylines. As Book Joe says, “The problem with books is that they end.” The good news is the wait is almost over. You Season 4, Part 2 drops next month on Netflix on March 9, followed by For You and Only You, the fourth book in the Joe Goldberg novels, out on April 13, 2023.