My son Asher helped me with this trailer, so of course I'm slightly ridiculously proud of it.

Kirkus called The Mostly Invisible Boy “a splendid conception” and no wonder: Casey Grimes thinks his invisibility is permanent until he finds a secret forest society in charge of monster control. Now he’s got a chance to belong—if he can stay alive long enough! "Original and inventive, full of courage and heart" (Amy Wilson, author of A Far Away Magic, Shadows of Winterspell, and The Wild Way Home). 


Need friends?—try fighting monsters.

In this "gripping fantasy adventure" (The Wishing Shelf Book Awards), Casey Grimes begins his studies at Trickery School, one of America's premier monster-control academies. But classes like Extreme Climbing and Land Creature Defense are the least of his worries. He realizes a mysterious enemy is after him—more cunning than a Bog Creep or Hyena Toad. And this secret adversary is playing for keeps. 


Classes have begun. Please don't die. 


Track the ghost cat! 

Step into the shiny sneakers of the irrepressible Lila Banks as she follows her cat Orangesicle—and fights to survive the night—in a forest where trails move around, strange creatures prowl, and pets are not always what they seem. When Lila decides to take a hike on her twelfth birthday, she doesn't expect to be stalked by the ghost of her recently-deceased cat. He was never very nice, but trying to eat her takes unlikable to a whole new level. This short story is a fun, spooky standalone backdoor into the magnificent Sylvan Woods world.

Praise for Casey Grimes

Silver Medal, Wishing Shelf Book Awards 2020

Bronze Medal, Readers' Favorite International Awards Contest 2020


"A steppingstone path of small mysteries and action scenes. Sylvan Woods is a splendid conception... Fast-moving and exuberant, packed with imagination." Kirkus Reviews

"The Mostly Invisible Boy excels...venturing into unpredictable territory, combining the feel of a fantasy with a treasure hunt." – Midwest Book Review


“A fun, exciting read...a rich, enticing world. A true adventure, where the stakes are high, the danger real, and [the] goal is almost impossible to reach.” – Bookworm for Kids


“Brimming with intrigue, danger and humor.” – Book Craic

“Vanderhorst has created a character in Casey Grimes who is so relatable, and so tangible...a must-read fantasy novel for middle grade readers.” – Frank Morelli, author of No Sad Songs and the Please Return To series


"Original and inventive, full of courage and heart."  – Amy Wilson, author of A Far Away Magic, Shadows of Winterspell, and The Wild Way Home


"Fun, funny and imaginative, The Mostly Invisible Boy is a rollicking good adventure."

– Andrew Chilton, author of The Goblin’s Puzzle 

"The Mostly Invisible Boy is a gripping book from start to finish...riveting." – LitPick

"Yikes, Butcher Beasts and Bog Creeps. These monsters have their own agenda. Perfect for middle grade—not too scary but enough to keep you flipping the pages. Surprises at every turn keep the plot moving at a quick pace." – Always in the Middle

“Vanderhorst connects to the deep feelings many middle school children deal with day in and day out.” – Reader’s Favorite five-star review

“Enchanting and unusual…the story entertains from the first page to the last." – Story Sanctuary

"A gripping fantasy adventure." – Wishing Shelf Book Award

"Incredibly imaginative and fun."– Book Pipeline

"Likable characters, clever plot, and unexpected twists and turns." – Indie Reader


The Mostly Invisible Boy: Long Description


Eleven-year-old Casey Grimes is stubbornly friendly, but he’s eternally the new kid at Vintage Woods Middle School. Students look right through him—and they’re not faking. Casey doesn’t know why he’s mostly invisible, but when he scales a colossal oak, he discovers a fortress in its branches. The forgotten sentry tree marks the border between his safe, suburban life and a fierce frontier.


Casey and his little sister Gloria infiltrate Sylvan Woods, a secret forest society devoted to ancient, wild things. Sky-high footpaths. Survival sewing. Monster control. Shockingly, people here actually see Casey—but being seen isn’t enough. He wants to belong. Posing as a Sylvan girl’s cousins, he and Gloria enter Trickery School—an academy where classes have surprise endings, battles are as common as breakfast, and magic is so last century. For the first time in his life, Casey makes friends…but kids at Trickery have lost touch with the people they’re sworn to defend. If anyone finds out he’s an imposter, he’ll be blacklisted for life—or worse, thrown in the sewers with the tiger rats.


Keeping his identity hidden—while struggling to prove he fits—is hard enough, but butcher beasts have returned to Sylvan Woods after a hundred years. Trickery is under siege. As the monsters close in, and the fearsome Sylvan Watch hunts Casey down, he and his newfound friends must unearth abandoned magic, buried at the forest’s roots…or be devoured along with everyone else, Sylvans and civilians alike.

For kids aged 7+ and adventurous grown-ups.