Two middle-grade kids take a shortcut home from school and discover what looks like fuzzy mud but is actually a substance with the potential to wreak havoc on the entire world.

When the lethal plague known as the Scourge returns to Keldan the victims are sent to Attic Island, and Ani Mells of the River People is among them--but Ani does not feel sick, and with the help of her best friend, Weevil, she sets out to uncover the truth of what is happening, and expose the lies the people of Keldan have been told.

Thirteen-year-old Sik wants a simple life going to school and helping at his parents' deli in the evenings. But all that is blown to smithereens when Nergal comes looking for him, thinking that Sik holds the secret to eternal life. Turns out Sik is immortal but doesn't know it, and that's about to get him and the entire city into deep, deep trouble. Sik's not in this alone. He's got Belet, the adopted daughter of Ishtar, the goddess of love and war,...

Someone who goes by the name of "V" is planning to unleash a lethal virus that could destroy the human race, and it is up to Nikki Tesla and her friends from the Genius Academy (which has been blamed for an international incident and shut down), to uncover the villain (who is closer to them than they realize) and find a way to stop the biological attack--an effort that will cost Nikki her life.

Rory Rooney likes to be prepared for anything, but when he inexplicably turns green and finds himself in an experimental hospital ward with his nemesis, school bully Tommy-Lee "Grim" Komissky, everyone is baffled but Rory believes he and Grim have become superheroes.

When a deadly disease breaks out, it is up to Anthea and her friends in the Horse Brigade to transport medicine throughout the kingdom while avoiding Anthea's evil mother and uncovering a powerful secret.

Twelve-year-old Jack may be the Imagine Nation's only hope of fending off a new Rustov attack, with the help of his fellow superheroes-in-training, but the virus he carries, and Jonas's suspicions, provide new complications.

When a mysterious illness sweeps through school, causing students to change color, sixth-grader scientist Wilmer Dooley tries to find the cause and cure.

"Morrigan Crow and her friends have survived their first year as proud scholars of the elite Wundrous Society, helped bring down the nefarious Ghastly Market, and proven themselves loyal to Unit 919. Now Morrigan faces a new, exciting challenge: to master the mysterious Wretched Arts, and control the power that threatens to consume her. But a strange and frightening illness has taken hold of Nevermoor, turning infected Wunimals into mindless, vicious...

When the strange symptoms of Zeke's flu cause him to ruin a skit he is in with his human classmates, he uses his alien powers to try to set things right.