Kate is a “switcher,” able to change into any animal she chooses—hawk, rat, etc. Throughout the trilogy she and a fellow switcher must battle evil forces who are trying to turn the world into a global glacier, and time: once a switcher turns 15, he or she must choose a final animal form.
Sequels: Midnight's Choice, Wild Blood
When sixteen-year-old Beka becomes "Puppy" to a pair of "Dogs," as the Provost's Guards are called, she uses her police training, natural abilities, and a touch of magic to help them solve the case of a murdered baby in Tortall's Lower City.
This is Book 1 of The Legend of Beka Cooper and is a "prequel" story about an ancestor of many of this author's other books' characters.
While working at pleasant but mundane summer jobs in San Francisco, fifteen-year-old twins, Sophie and Josh, suddenly find themselves caught up in the deadly, centuries-old struggle between rival alchemists, Nicholas Flamel and John Dee, over the possession of an ancient and powerful book holding the secret formulas for alchemy and everlasting life.
Book 1 of The Secrets of the Immortal Nicholas Flamel
Fifteen-year-old Matt and his new friend Robin search the globe to retrieve an ancient code--rumored to have brought down the ancient civilization of Atlantis--from the hands of a madman who is bent on destroying the modern world. Cool mix of modern technology and ancient mystical magic.
Fifteen-year-old Daniel has followed in his parents' footsteps as the Alien Hunter, exterminating beings on The List of Alien Outlaws on Terra Firma, but when he faces his first of the top ten outlaws, the very existence Earth and another planet are at stake.
Sequel: Daniel X: Watch the Skies