A World Without Heroes is the first book of the Beyonders series, written by Brandon Mull.
"Jason Walker has often wished his life could be a bit less predictable- until a routine day at the zoo ends with Jason transporting form the hippo tank into a strange imperiled world.
Lyrian is full of dangers and challenges unlike any place Jason has ever known. The people live in fear of their malicious wizard emperor, Maldor. The brave resistors who once opposed Maldor have been bought off or broken, leaving a realm where fear and suspicion prevail.
In his search for a way home, Jason meets Rachel, who was also mysteriously drawn to Lyrian from our world. Jason and Rachel become entangled in a quest to piece together the word of power that can destroy the emperor, and learn that thier best hope to find a way home will be to save this world without heroes."
While working at the zoo one day, thirteen-year-old Jason Walker falls into the hippo tank and is swallowed whole by the hippo. To his surprise, Jason emerges out of a tree on a Lyrian riverbank and manages to save the life of Tark. Shortly afterward, he finds his way to the Repository of Learning, goes into the forbidden room and finds the book of Salzared, “bound in his skin and written in his blood." In the book, Salzared tells the reader about the Word that can destroy Maldor, saying that “the first syllable is a.” The loremaster, telling Jason that his knowledge now makes him wanted by Maldor, sends him to the Blind King, where Jason meets Rachel, another Beyonder. Beyonders are people who come "the Beyond", such as our world or one of many others.
The Blind King sends them on a quest to find the rest of the Word. They travel across Lyrian, making many friends and enemies and gradually piecing together the Word, until Jason is captured. He is brought to Felrook, the abode of Maldor himself and the most fortified castle in Lyrian. Jason uses the Word on Maldor, only to have it fail. Maldor informs him that the Word is a fraud, meant to distract his enemies. After undergoing torture for some time, Jason escapes with the help of Ferrin, who takes him to a secret portal back to the Beyond. Jason determines to eventually help Rachel get back home too.