Have you read The Dark Is Rising Sequence? I was browsing a Harry Potter discussion forum when I found a reference to this series.

Written by Susan Cooper, The Dark Is Rising Sequence consists of five books aimed at a teenaged audience. The first book, Over Sea, Under Stone, published in 1965, begins the story of siblings Simon, Jane, and Barnabas Drew, who discover a treasure map. They embark on a quest to find a grail that's been hidden for over 1,000 years and eventually confront the forces of evil.

The series sounded like a great combination of fantasy and mystery, so I bought the box set last week. The books run between 125-275 pages, so the series will probably be a fast read. I'll post a review sometime this week.

If you've read the books, you may post a spoiler-free review in the comment section.

Update (1/3): These stories are whetting my appetite for more Christian fantasy. Fascinating stuff. I'm on Book 2 of the five-book series. More later.