Lin Moser is not looking forward to this summer. After living on the road all her life, hiking mountains and traveling through the country in an RV with her house-flipping parents, she’s now stuck in Newbridge, New Jersey for their longest stay yet. With Mom away on a year-long naturalist assignment, Lin has resigned herself to having the most boring summer ever. But then she finds out about a local legend: an ancient ruined castle in the woods that no one has been able to find. Hiking to this castle would be like a quest … such an amazing quest, perhaps, that Mom might even come home and join her, like it used to be.

Determined to create her own adventure, Lin sets off on her biggest one yet-braving the wilderness with her two new friends, finding the castle, and maybe discovering home along the way.