It's summertime for supervillains! Or maybe not, because for Penelope Akk, there is still one foe she has yet to defeat: her own reputation as Bad Penny. It's been a fun ride: fighting adult heroes, going to space, and inspiring the rest of her school to open up about their own powers. Sooner or later, that ride has to end, and with school out of the way Penny is hatching a mad scheme to end it on her own terms. Will that go smoothly? Of course not. Penny's left too many unsolved problems behind her already, like ghosts, seriously crazy friends, and angry little girls from Jupiter. One by one, they'll have to be dealt with before she can do battle with herself. She'd better hurry, because her parents are closing in. Whether she confesses or not, this time they will find out her secret.

Penelope Akk wants to be a superhero. She's got superhero parents. She's got the ultimate mad science power, filling her life with crazy gadgets even she doesn't understand. She has two super powered best friends. In middle school, the line between good and evil looks clear. In real life, nothing is that clear. All it takes is one hero's sidekick picking a fight, and Penny and her friends are labeled supervillains. In the process, Penny learns a hard lesson about villainy: She's good at it. Criminal masterminds, heroes in power armor, bottles of dragon blood, alien war drones, shape shifters and ghosts, no matter what the super powered world throws at her, Penny and her friends come out on top. They have to. If she can keep winning, maybe she can clear her name before her mom and dad find out.

What do you do when you have the wrong super powers? Magenta's older brother is a superhero. She's starting high school at the school where kids with powers go, including the famous Inscrutable Machine. Except, Magenta's powers are no good for fighting. Her potions are useful, not dangerous. Her other power is just humiliating. What Magenta has plenty of is determination, and she tries fighting a supervillain anyway. She fails. But for Magenta, failure is the beginning, not the ending. Suddenly she has a part-time job working for that same supervillain, who doesn't seem very villainous. She spends her afternoons buying mad science from smugglers, copying memories into a magic book, delivering messages to evil lawyers, and always, always, putting on a show. Soon, she's ducking heroes who want to save her from herself, and her best friends, who don't know the sidekick they're chasing is Magenta. Making sure her parents don't find out is the easy part.

Middle school supervillain Penny Akk has defeated every challenge thrown against her. She has bested heroes, villains, weirdos who can't make up their minds, robots, aliens, friends, rivals, enemies, natural disasters, secret admirers, and her own shyness. Now she has only one opponent left. Her own super power. ...and the other Penny who stole it.

Supervillains do not merely play hooky. True, coming back to school after a month spent fighting—and defeating—adult superheroes is a bit of a comedown for The Inscrutable Machine. When offered the chance to skip school in the most dramatic way possible, Penelope Akk can't resist. With the help of a giant spider and mysterious red goo, she builds a spaceship and flies to Jupiter. Mutant goats. Secret human colonies. A war between three alien races with humanity as the prize. Robot overlords and evil plots. Penny and her friends find all this and more on Jupiter's moons, but what they don't find are any heroes to save the day. Fortunately, they have an angry eleven-year-old and a whole lot of mad science…

What would middle school be like if half your classmates had super powers? It's time for Penny Akk to find out. Her latest (failed) attempt to become a superhero has inspired the rest of the kids in her school to reveal their own powers. Now, all of her relationships are changing. She has a not-at-all-secret admirer, who wants to be Penny's partner almost as much as she wants to be Penny's rival. The meanest girl in school has gained super powers and lost her mind. Can Penny help her find a better one? Can she help an aging supervillain connect with his daughter, and mend the broken hearts of two of the most powerful people in the world? And in all this, where will she find time for her own supervillainous fun, or even more dangerous, to start dating? It's going to be a long, strange semester.

When an evil artifact offers you the power to turn into a monster, agreeing would be stupid. Mirabelle isn't stupid. She also doesn't have much choice. Her friends all have super powers that let them go on exciting adventures. Mirabelle's super power is to be made of glass, and walking across a room is dangerous enough. But the shiny rock won't shut up, and to get rid of it, she has to use its powers against it. She does that carefully, because Mirabelle isn't stupid. Until Mirabelle falls in love, and love makes everyone stupid. Now supervillains and superheroes are fighting over four pieces of the Heart of Vermiel, and a girl who breaks if she runs has to collect them all, or be broken. She has to turn into a monster on the outside without turning into a monster on the inside. Somewhere in this mess there has to be an ending that lets her stay alive, stay a good person, and maybe get a chance to run, and be angry, and break things just once. Besides, how many girls can say their boyfriend is a dragon?