Summary

• Each book in The Mortal Instruments series reveals a thrilling adventure filled with magic, danger, and intrigue, but every book has its highs and lows.
• City of Fallen Angels sets the stage for future books, making it less action-packed but crucial for the series.
• City of Heavenly Fire is the ultimate conclusion to Clary's journey, delivering a fast-paced, satisfying, and epic finale.

In 2007, author Cassandra Clare released the very first book in her 2013 The Mortal Instruments movie adaptation and a 2016 TV series. Clare went on to write three more series, taking place in the same magical world over several generations.

Though each Mortal Instruments book follows a particular plot, the overarching story is the same. Teenager Clary Fray's life is turned upside down when she discovers the existence of Shadowhunters: angelic warriors dedicated to ridding the world of demonic entities. After her mother goes missing, she enlists the help of the Shadowhunters to figure out how she fits into this fantastical puzzle. What she learns leads her to uncover a sprawling world of danger, magic, and good and evil. Despite following the same trajectory, the Mortal Instruments is that each book has its pros and cons.

6 City Of Fallen Angels

Book Four Of Six

What is likely considered to be the worst Mortal Instruments book of the six is City of Fallen Angels. This is the fourth book in the series, and notably, is the shortest at 425 pages. On Goodreads, its average star rating is 4.08, with a total of 607,000 ratings. City of Fallen Angels is ranked last on this list not because it's a bad book, but because it isn't entirely necessary to the plot.

City of Fallen Angels takes place directly after the events of City of Glass, wherein the Shadowhunters fought and won The Mortal War. Clary returns home to New York, believing that everything is right with the world. She is training to become a Shadowhunter, her mother has found love, Shadowhunters and Downworlders are at peace, and most importantly, Clary and Jace can finally be together. However, when a string of murdered Shadwowhunters show up around the city, Clary realizes that she set off a dangerous chain of events that could ruin everything, and worse, lead to another war.

Because City of Fallen Angels is a book meant to set up other books, it is likely the least popular Mortal Instruments story.

City of Fallen Angels is the least action-packed book in The Mortal Instruments. Where other books center on major battles, travels, and plot points, City of Fallen Angels takes a slower approach. A big part of this is because it is a book about resolution and set-up. It needs to tie up the loose ends of City of Glass while also gearing up for the huge events set to happen in the second half of the series. Because City of Fallen Angels is a book meant to set up other books, it is the least popular Mortal Instruments story.

5 City Of Ashes

Book Two Of Six

City of Ashes ranks fifth among The Mortal Instruments books. It is the second overall book in the series. Its Goodreads star rating rests at 4.11, with 943,000 total ratings. As the second book in the series, City of Ashes is popular, but its storyline puts it at the bottom of the list.

Where the first Mortal Instruments book introduces readers to the world of Shadowhunters, City of Ashes immediately raises the stakes. After discovering that she is a Shadowhunter, Clary is overwhelmed with confusion and fear. She needs to figure out how to break her mother's magically induced coma, while also tracking down the evil Shadowhunter Valentine, who also happens to be her father. On top of that, Clary comes to with the fact that her former love interest, Jace, is her brother, and may just turn evil to please their father.

Overall, City of Ashes is so poorly rated among The Mortal Instruments series because of its plot. Watching Clary try to unravel so many Shadowhunter secrets on her own is incredibly hard to read, especially since she has been a part of this world for such a short time. Worse, all her relationships are changing, as Simon develops feelings for her and Jace becomes more distant. However, the worst part of City of Ashes is the squicky storyline of Clary and Jace believing they are siblings but still being attracted to one another. After rooting for their romance in the first book, it is excruciating to see them as siblings.

4 City Of Bones

Book One Of Six

The book that rests in the middle of The Mortal Instruments ranking is City of Bones, the very first book in the series. Since its release in 2007, it has garnered the lowest Goodreads score of The Mortal Instruments books, with a 4.07. However, it also has the most ratings of the entire series as well, with 2 million ratings. Notably, City of Bones is the basis for both on-screen Shadowhunters adaptations.

City of Bones is the adventurous and fantastical introduction to The Mortal Instruments series. In it, readers meet Clary, a normal teenage girl who gets sucked into the world of Shadowhunters. Through her eyes, readers also see Jace, a cocky yet talented Shadowhunter. By the end of the first book, Clary learns about her place in Shadowhunter society, but also becomes trapped in a scheme that is even more complicated than the first.

The 2013 movie, The Mortal Instruments: City of Bones starred Lily Collins as Clary Fray and Jamie Campbell-Bower as Jace.

Though City of Bones has the worst ranking of the six The Mortal Instruments books, it ranks fourth because of its nostalgia value. City of Bones has a strong story that was clearly successful enough to suck readers into five more novels. In this book, Cassandra Clare succeeds at establishing an exciting world that is a launching point for the rest of the series. That being said, City of Bones does not have the most compelling plot of the six books, simply because it needs to set up a lot. Therefore, it sits in the middle of the ranking.

3 City Of Lost Souls

Book Five Of Six

Coming in third for the best The Mortal Instruments book is City of Lost Souls, the fifth and penultimate book in the series. It is the second-longest book, at 535 pages, making it a substantial read. On Goodreads, it has a 4.22 star rating, with a total of 536,000 ratings.

City of Lost Souls follows Clary in the aftermath of Jace being magically connected to her evil brother, Sebastian. Forced to work for the dark side, Jace is unreachable, and also in danger of being taken down by the Shadowhunter government. As Jace and Clary's friends try desperately to find a solution, Clary forges her own battle against Sebastian to regain the one she loves. However, Clary can't help but wonder if Jace is too changed to be worth saving.

City of Lost Souls seems to have little going on, but its slow burn quality makes it one of the best The Mortal Instruments books.

Based on its synopsis, City of Lost Souls seems to have little going on, but its well-paced quality makes it one of the best The Mortal Instruments books. As the fifth book in the series, City of Lost Souls has no need for exposition. Unlike some of its predecessors, it can jump right into the drama, making it a more riveting read. Plus, City of Lost Souls has major stakes. With a war brewing and Jace in immediate danger, this book builds the tension so it is ready to explode in the sixth and final installment.

2 City Of Glass

Book Three Of Six

The second-best book in Cassandra Clare's The Mortal Instruments series is City of Glass. The third book in the series has an impressive 4.28 star rating on Goodreads, with 939,000 ratings. City of Glass' genius is that it is the unexpected and explosive end of the series' first half.

In City of Glass, Clary must travel to the magical land of the Shadowhunters to save her mother, but entering without permission means a high likelihood of death. To make matters worse, Jace doesn't want Clary to go and Simon is imprisoned for his Downworlder status. Ultimately, Clary forms a bond with a unique Shadowhunter named Sebastian to bring together the Shadowhunters and Downworlders and overthrow Valentine for good.

Although City of Glass is the third book in The Mortal Instruments, it gives readers a true climax. City of Glass is like the finale to the first half of the series, and this makes it one of the most memorable installments in the series. Readers do not have to wait until book six to get an all-out war or answers to their burning questions. City of Glass and its unexpected deaths offer an outstanding ending before the real ending. It is propulsive, exciting, and a solid end to the first half's biggest problems.

1 City Of Heavenly Fire

Book Six of Six

The book that is easily considered the best of The Mortal Instruments series is the sixth and final book, City of Heavenly Fire. This is by far the longest book of the series, coming in at 725 pages. Its Goodreads star rating is 4.39. It also has the least number of reviews of all six books, with 388,000 reviews.

City of Heavenly Fire is the intense ending to Clary's journey among the Shadowhunters. Clary and her friends find themselves in peril against Clary's brother, Sebastian. He has stolen the Infernal Cup, and is using it to turn Shadowhunters into terrifying monsters. With all the Shadowhunters hiding out in Idris, there is nowhere left to run and no one to protect the human world from demons. Backed into a corner, Clary, Jace, and their peers must dive into realms no one has ever gone into before to find a way to defeat Sebastian for good.

Regardless of its page count, City of Heavenly Fire is the most fast-paced and action-packed book in the entire series. Every second counts in this novel, as Clary races against the clock to take down her brother. What makes this book truly stand out is that it wraps up everything in a satisfying way, while also setting up for the other Shadowhunter book series. It makes all five books that came before incredibly worth it. Cassandra Clare's final battle is epic, heartbreaking, and engaging. In this way, there's little doubt that this is the best The Mortal Instruments novel.