Continuity Problems

There are various continuity problems, inconsistencies, and dropped plot lines throughout the series.

The Angel Experiment[]

Iggy gets a golden hoop earring while at U 'Do: Tomorrow's styles today, but it is never mentioned again.
The bank card is not mentioned after this book.
There is a "second Flock" of various mutants that the flock liberated from the Institute for Higher Living, but they are never mentioned again.

At the end of The Angel Experiment are some posts from Fang's blog, describing how he and Nudge scout out Washington, D.C. before the Flock. This trip takes several days and seems to be set between Book 1 and Book 2. However, at the beginning of School's Out - Forever, Max specifies that only one day passed between books.
When was Iggy taken from his parents? In the first book, the files said first that Iggy's mother was dead and then that his father was dead, but in this book they are both alive. However, a reporter says that Iggy was kidnapped from the hospital as a newborn, while Mr. and Mrs. Griffiths tell Iggy that he was taken from their house when he was four months old.
This book begins one day after the end of The Angel Experiment, and Angel says she was at the School "last month." However, she was kidnapped in May and only held for a few days, and this book takes place in autumn.

It has been “five months” since Angel was kidnapped, but that would place them in October; they’ve already celebrated Thanksgiving.
In the previous book, Ari had signed "Wolverine" on a kid's shirt without much hesitation; however, in this book, Max has to teach him how to write his own name.
Max says that Fang’s mother gave him up for adoption. This was not mentioned in the previous book.

Dropped Plotlines

At the end of The Angel Experiment, the Flock prints a bunch of papers about themselves. These turn out to be dead ends, and there's a mention that they seem to have been tampered with while at Anne's house. In this book, Jeb suggests that all of this evidence was faked. However, after this book, the Flock never mentions their parents again, even though Iggy and Max are the only ones who found theirs.
The Director, other Itex employees, and other experiments, including clones of Nudge and Angel, are not mentioned again.
Jeb is revealed to be the Voice. This is retconned in the next book, but it is never explained how he knew of the Voice's existence (as it was always inside Max's head) or how he was able to mimic it perfectly.

Dropped Plotlines

Angel's new powers.
The Lerner School which is opened for mutant kids. The Flock attends two other schools in the following books, but this one is not mentioned.

Hollywood agent Steve Blackman set up an appointment with the now world-famous Flock hoping to do business with them, but at the appointment, Max is the only one he actually knows by name.
In the previous book, Dr. Brigid Dwyer's hair was said to be blond; however, in this book, it is red.
Max calls Brigid Fang's "favorite brilliant, underage scientist," but in The Final Warning, she told the Flock that she's twenty-one.
Angel mentions eating chocolates in France which turned out to contain alcohol and made Gazzy sick. The girls visited France in Saving the World and Other Extreme Sports, but Gazzy was in California at the time.
Angel manipulates robots, which should not be possible.

In the previous book, Nudge had gotten a bed to herself since she kept kicking people in her sleep; however, in this book, she sleeps right next to Max, and Iggy is off in one corner, since he is "the famous restless sleeper."
It's mentioned that Angel no longer sleeps with Celeste, the ballerina bear. Celeste was introduced in The Angel Experiment as an angel teddy bear, with wings, a gown, and a halo.
After a visit to the museum, Iggy tells the others, “I learned something about myself... I learned I want to see." Max is stunned, as “Iggy had never said that” and “We totally took for granted that his superior extrasensory skills seemed to give him pretty much the same abilities and quality of life the rest of us had.” This contradicts Iggy’s behavior in The Final Warning and especially in School’s Out – Forever, where he admits to how scared and vulnerable he is and tells them, “Of course I need to see!”
In Fang's files at the end of the book, there are some questions from a fan, who claims, "I’ve commented your blog with my questions for THREE YEARS." In-universe, Fang's blog can only be less than a year old, as it is a minor plot point that the Flock is about a year older than they were at the beginning of the series.

Dropped Plotlines

In FANG, Fang gives Max a birthstone ring. Here, it is referred to as a promise ring instead.
In Saving the World and Other Extreme Sports, Max and her mini-Flock had encountered Max II at Itexicon headquarters in Germany.
Max says in this book that she remembers Angel saying that "Maya spent most of her time in Europe after she was liberated from her cage in New York." The Flock freed numerous experiments including a winged girl from the Institute in The Angel Experiment; however, Max II was last seen imprisoned in Germany and it is unclear when she was in New York.
- Maya also says to Max, "Gee, I haven't seen you since you tried to kill me." Again, their last meeting was in Germany, where they talked peacefully.

Dylan is said to be 2 years old, but only a few months have passed since he was said to be 8 months old in FANG.
Max says that she hasn’t seen Ella since Dr. Martinez “had her rescued and squirreled away from the 99% cult, who almost had her brainwashed,” implying that Max witnessed this. However, both Ella and her mother were last heard from when they vanished, separately, in ANGEL; Ella was brainwashed by the 99% cult, while Dr. Martinez was brainwashed and working with the whitecoats.
Angel is revealed to be the Voice. This leaves the identity of her own Voice, in FANG, a mystery. The Voice also instructed other members of the Flock including Dylan and Ari, including prompting Dylan to kill Fang, which make Angel's motives unclear.

At the end of Nevermore, Iggy, Nudge, Gazzy and Total last seen heading underground with Dr. Martinez and the others. At the beginning of Maximum Ride Forever, they are all aboveground with no explanation.
During the final battle, Max flies the Remedy "high into the atmosphere and east over the ocean." When she drops him, he lands on the ground.

In The Angel Experiment, Max mentions that Angel likes small, cozy space; however, this contradicts the fact that the entire Flock is claustrophobic, as said by both Max and Fang at different points in the series.
Max’s hair color is in flux – blond in School's Out - Forever and Saving the World and Other Extreme Sports, but brown in following books. Her sun-bleached streaks remain, but the narration does switch from primarily calling it blond to primarily calling it brown. Other characters with inconsistent hair colors are Iggy and Dr. Brigid Dwyer.

In First Flight #2 and Final Flight #1, Max has a tracking chip located in her right wrist (changed from the books, where it was her left wrist). However, in Ultimate Flight #4, the chip is located in her right shoulder instead.