Jack Blank's history is unknown to him, but everything changes when he's attacked by one of the supervillains from his comic books and wisked away from St. Barnaby's by an emissary, Jazen Knight, of a secret country: the Imagine Nation. Jack arrives to the Imagine Nation at twelve, only to discover that his favorite super heroes, and more, exist in this secret place, as well as a connection to it. Along with it, he discovers he is a key player between the never ending war between the Imagine Nation as their enemy, the Rüstov. Suspecting he's a Rüstov spy, a suspicious aroused by Jonas Smart, Jack does all that he can to prove the contrary, enough to be offered an entrance exam with the School of Thought, a special academy taught by the very leaders and protectors of the country. His impatience to know more of his past leads to the death of Jazen Knight, discovering that in his future he will become the enemy's supersoldier, Revile, and yet, gaining the favor of the Imagine Nation as a hero after an ultimate fight with himself.
Feeling guilty by the fame, Jack decides to keep a secret that he will turn into Revile, Stendeval his confidant, who believes Jack can change his future. A year after the fight, Jack continues with the struggle of making a cure of a spyware virus that will turn the innocent Mechas of the Imagine Nation turn against their fellow citizens. It becomes a race against time as a rogue Secreteer announces that in five days' time, the Rüstov will return and annihilate the country and the rest of the planet. Along with his friends, Jack tries to stop this new Rüstov invasion as well as make the cure, discovering along the way that the parasite that lives within hims is none other than the son of the Rüstov emperor, Khalix. While nearly destroying his friendship, he manages to both stop the invasion and make the cure that barely save the Mechas, even their leader, Virtua, as well as revive his old Mecha friend, Jazen. Despite it all, the Rüstov manage to capture Jack.
Another year afterwards, after mysterious distress calls that supposedly come from Jack, his friends manage to save Jack and escape back to the Imagine Nation, whom now all think that Jack isn't just a traitor, but believe him to already have turned into Revile. During the debate, the Rüstov Armada send the first wave of the second invasion to the Imagine Nation, which Jack, without thinking, helps but fight back. Even after being victorious, Jazen is captured by Smart and Jack is still put to question, almost killed publicly in Varagog Village by his then former friend, Skerren. Jack is saved though by his friends, only to be attacked once again by the Rüstov, who take back Jack, along with Stendeval, Allegra, and Solomon. In one final attempt, Stendeval helps Jack escape, leaving behind all three who are infected by the Rüstov, Stendeval dominated by the Magus himself. After escaping, Jack reunites with the few allies and friends he has left, managing to formulate a plan to keep his own infection at bay and try to beat the Rüstov. In the end, the infection wins over, but with Smart's aid, surprisingly, Jack manages to push Khalix away from controlling him, Jack using the infection to his advantage to fight back the Rüstov, even calling for help from his future self, Revile. With Revile and the rest of his friends, Jacks makes way to the mothership to save the others and defeat the Magus. After their victory, Stendeval returns Jack to his former self, and the Imagine Nation celebrate Jack as one of the best heroes in history, as well as finally reuniting with his father, Solomon.
Jack Blank is a teen boy. Throughout the books, he goes from age 12 to 14. The rest of his 'appearance' depends on how you depict the book.
Jack is a very brave and loyal young boy who wants nothing more than to understand who he is and where he comes from. Despite his unclear past and connection with the Rüstov, Jack is faithful to the Imagine Nation, as well as a dedicated student in the School of Thought. He's also creative when the situation calls for it and his powers are seemingly useless, and thoughtful of others. Jack can be fearful as well, especially when it comes to his parasite and his future, immediate or otherwise. He's reckless at times, especially when the situation is dire and his friends are in need.
At the beginning of the series, Jack is completely alone, though looks up to Jazen as an older brother soon after arriving to the Imagine Nation for the first time. There are hints that he sees as Stendeval as more of a father than a mentor on occasions. In the third book, Smart reveals that Jack's father is Clarkston Noteworthy, the current Circleman of Hightown. While Noteworthy refuses him until Jack is hailed as a hero, it is later discovered that while Jack is definitely a Noteworthy, he is actually son of Solomon Roka, Clarkston's brother, whose memory was erased by the Secreteers after having a forbidden affair with one of them. Jack's mother was a victim of the Rüstov parasite during the first invasion, so it is assumed she died at some point during the Battle of Empire City.
Jack has the ability to manipulate and talk to machines. The more he understands a piece of machinery, the easier it is to manipulate. Jack also explains that machines have personalities, which can be a bit of a complication when he tries to control them. He can also detect any incoming machine. His powers are what many, himself included, suspect that help him fight his own parasite. While he is powerful, especially as he becomes more knowledgeable with machines throughout the series, Jack can easily control the Rüstov (as they are considered machines,) and the more rotten they are, the easier, but by the third book, he cannot control them due to the parasite of Khalix inside him.
In the second book, Jack demonstrates he's been studying engineering and computer sciences, not just to understand machines, but also make his own inventions, which serve purpose in some missions and battles.
In the last book, when Jack allows for the infection to take over, Jack is able to manipulate all machines as before, as well as regenerate whenever he is hit mortally, unable to die in battle. He also uses missiles, wrist cannons, and other weapons that can be attached to his body while regenerating.
Jazen is the first person from the Imagine Nation that Jack comes into contact with. Jazen was sent to find Jack by Stendeval, who secretly had been watching over him for all his life in St. Barnaby's. During their trip to the secret country, Jazen explained all that he could about it to Jack, and trusted him from the beginning that he was a special boy bound for greatness, something he wasn't far from being wrong. At the end of the first book, Jazen dies trying to protect Jack from the Rüstov who wanted to take him. Jack mourns him deeply and kept his remains, (Jazen is a Mecha, an android,) to use and experiment to find the cure to the spyware virus, with which Jack discovered with Jazen moments before Jazen died. Jazen is brought back to life, proving the cure works. In the third book, Jazen is one of the people that helped save Jack from the Rüstov and helped him in the last battles against the Rüstov Armada. Jack looks up to him like a big brother.
While at first surprised to see a giant person with blue skin, Jack warms up to the Empire City cop very quickly. Both are very good friends, and despite his intimidating look, Blue has a soft side and cares for Jack, enough to risk his own life as much as Jazen had. Both Blue and Jack trust each other, despite the few secrets that Jack kept, but never doubt each other, in battle or otherwise.
Unbeknownst to him, Jack was watched over by Stendeval all his life, from the moment he got to St. Barnaby's. Protected by the Circleman of Cognito, Stendeval never doubted that Jack could do good and could change his future, always helping him see through the fear of Jack turning into Revile. Stendeval also stood by his side when trying to find the cure and keep the secret of him turning into Revile with him, and sacrificed himself to help Jack escape by becoming the host body of the Magus. Jack appreciates Stendeval very much, as if he were his own father.
One of the kids he first meets about his age, Allegra is initially very fearful of Jack due to his connection of his parasite, especially considering her history with the Rüstov. However, she warms up to him fairly fast, and both become the best of friends throughout all three books, despite the secrets Jack did keep in the second. There are hints that maybe they hold romantic feelings for each other, such as the many times that Allegra morphs her arms to shields and/or swords to fight back enemies coming toward Jack or the young boy giving a communication bracelet that fits just right with her.
At the beginnign of the series, Skerren and Jack might as well despise each other. Skerren's own history with the Rüstov makes him hate Jack but while it takes time, he warms up to him, and both become friends after Jack first defeats Revile. The relation deteriorates in the second book when he starts to see through Jack's secrets. In the third book, Skerren is back to hating Jack for different reasons, though Jack, by then, is more hurt rather than hating his former friends. At the last fight, Skerren manages to put his anger aside to make an alliance with Jack, but once again, both boys become friends at the end.
From the very beginning, the two hated each other. Smart's fear and hatred against the Rüstov pushes him to basically start a campaign against Jack, which at the start, doesn't take much as nearly everyone in the Imagine Nation suspected Jack to be a sort of Rüstov agent. Initially, Smart wanted Jack executed and dissected, but with time, conforms with just killing him at every opportunity that he gets, especially in the second book, as he loses his position as Circleman of Hightown. While he does help Jack in the third book, the two keep hating each other at the end.
The Circleman of Galaxis, Jack looks up to Prime, as he heard of him first in his comic books before getting to the Imagine Nation. Prime is one of the few that doesn't fear Jack and trusts him that he can make his own path in his future.
The Circleman of Karateka, Jack idolized the kung fu master since his comic books. Chi also sees Jack as innocent, and trusted him from the start, especially as Stendeval had forewarned that Jack would arrive some day. Chi doesn't hesitate to help Jack in his studies.
The Circlewoman of Mecha, Jack had heard of her from his comic books. While Virtua defends Jack at the beginning, she has her suspicions, though Jack manages to prove himself to her. Things seem to deteriorate in the second book when Jack reveals he had always known about the spyware virus that threatens her and the androids of Machina. Jack proves himself once again when he cures them all and brings Jazen back to life. Virtua, soon afterwards, trusts Jack without second doubts.
The Circleman and King of Varagog Village, Hovarth wasn't entirely excited of Jack at the beginning, despite Jack's admiration for him from his comic books. Hovarth admits his mistakes though, during the entrance exams to the School of Thought and especially after seeing Jack first defeat Revile in Wrekzaw Isle. However, the two quickly come to disagreement when everyone starts to think Jack will become Revile at any moment in the third book, Hovarth, along with Smart, leading the people of Empire City to take Jack and kill him. They come to friendly terms, however, at the end of it all when Jack saves them all.
Former Circleman of Hightown, Jack never really met Legend, the hero of the first Rüstov invasion and who defeated Revile. However, Jack does appreciate Legend for having saved him along with Stendeval, even if it meant sacrificing himself to defeat Jack's future self.
The current Circleman of Hightown, Noteworthy and Jack don't get along that well. Noteworthy still doubts Jack and comes to hate him when he figures he'll turn into Revile, and when Smart reveals that the two are father and son, he hates Jack even more. After saving the Imagine Nation and the planet, Noteworthy decides to give Jack a chance, which Jack refuses, leaving the two with a grudge.
Jack is terrified of him from the start. Before knowing who he was, Jack faced him off at St. Barnaby's, but after learning that he is Jack's future, Jack fears the future is already set. Jack stops him by letting him melt over and over again in Wrekzaw Isle, leaving Jack to struggle what to do. Two years after, when Jack lets the infection take over, Jack frees Revile, this time, both fighting together against the Rüstov. Jack finally overcame the fear, even crying for him when Revile sacrifices himself to save his younger version.
Like everyone else in the Imagine Nation, Jack hates the robotic aliens, especially as he carries a parasite since he was a baby. The Rüstov want him for reasons unknown, at the start. Even so, Jack hates them and stops at nothing and will fight when the time calls for it.
The Prince of the Rüstov, he is the parasite that has been living inside of Jack since he was a baby. Jack didn't know of him until he arrived to the Imagine Nation, and didn't even know of who it was until he starts to investigate about the parasite with his powers. The two hate each other, fighting for control over Jack's body.
The Rüstov emperor, Jack hates him more than he hates Khalix. The Magus hates Jack just as much, but desires him as he is the host of his son. Still, both face off in the last battle for Earth, a last chance to conquer or be conquered.