The Dark is Rising series is rather like Star Wars in its theology...there is a balance between the dark and the light, but it is being disturbed, and the dark is rising. The light must turn it back. There are certain symbols of the “light”: A Grail, a harp, a crystal sword, six circles divided by a cross, etc.
In the first book, which starts out beautifully, with no heavy foreshadowing of what is to come, three children find a map, avoid the bad guys, and find the grail (not THE Holy Grail, I don’t think). Their uncle Merry helps them. Merry, it turns out, is an “Old One” who lives for centuries. In fact, he is Merlin, we find out in later books.
The second book, The Dark is Rising, is quite dark, set in winter, and revolves around the awakening of a new “Old One.” Will Stanton has just turned 11, and his status as an Old One is revealed to him. Lots of time travel, a bit of “mind control” evil characters, mysterious happenings. The role of “the light” and “the dark” is now revealed to the reader. A church (Anglican, we must presume), is a place of “the light”. So far, so good. But there are some troubling passages. In the church, during a conversation with the vicar, the Old Ones (people of “the light”) mention that the cross as a symbol of power is older than Christianity. The vicar counters with, “But not older than God.” The author tells us that the Old Ones remain silent on that point so as not to offend the vicar. As a read aloud, you can skip that line, and the whole book is fine.
In Greenwitch, there are many pagan references. It is a tradition in Cornwall for the young girls and women of the area to make a “greenwitch” out of green boughs, and send it to sea, off a cliff, with their wishes for a prosperous year. In this story, the Greenwitch is a real entity—an entity of chaos. There is also the sea goddess “Tethys”—neither of “the dark” nor of “the light”. The Grail is stolen and retrieved, and there is a bit of “mind control” used by both “the dark” and “the light”. Libby did not care for this one.
The Grey King, which is very good, includes time travel, Welsh history and language, shape-shifting animals, mind control, real evil, death of a beloved pet, unrequited love, and Guinevere. I really enjoyed this one, and I think you can read this one without having read Greenwitch. There is no specific reference to God, but there is some discussion of faith.
The last book, The Silver on the Tree, is very strange. It takes place in the lost country—almost like Atlantis—and addresses the issue of despair. It is quite confusing at times, and is only saved by the relationship between the characters. King Arthur finally shows up (more time travel), and all is set right <G>.
Overall, the books are very well written. The sentence structure is strong, as is the vocabulary. Between the child-characters, the sense of right and wrong are quite good. But the dark and light are not held to any standard when it comes to their own purposes. Morality is convenient for them, and the end does justify the means on both sides. I do recommend the books, but only for the well formed. As I’m sure I have said, I think most homeschooled Catholic kids are well-formed, and can read the books. After all, you’ll be there in case any issues are raised, and there won’t be a classroom full of moral relativists debating the issues with your kids.