I’ve been desperately searching for a book I read as a child in the early 2000’s. I was born in ’92 and would’ve been somewhere between 8 and 12 when I read this book.
I’m a bit fuzzy on details but I strongly believe this book was about these people who lived near a deep chasm in the human world and a young boy’s sister goes missing after being seen near it and it’s now his duty to find her. He traverses into the chasm and finds himself in a magical world. There’s definitely a griffin (or possibly a giant eagle ?) he ends up befriending. This is where things get fuzzy; I’m pretty sure he finds out his sister is dead and he and the griffin make her a grave. I’m pretty sure he ends up entangled in a war of some sort and helps the magical creatures triumph, but I’m not 100% sure on this. I’m pretty sure the griffin/eagle flies him back up the chasm at the end.
It’s basically like a fantasy story about this boy coming of age and proving his strength and bravery. It’s been driving me nuts for years because I remember so vividly loving this book but I can’t remember the name or author or much of the details, what sticks out most in my memory is the chasm and the griffin.