At one point, I read The Dark is Rising trilogy at Christmas every year, lining up the timeline of The Dark is Rising itself with the season, as the most obviously timed event in the books. I still maintain that it’s a good series: Cooper did some clever things with mythology and history. I recently read an article by Michael D.C. Drout, ‘Reading the Signs of the Light’, which made that very clear (though that essay is more focused on the second book of the series onwards than on this one). Cooper also has a very deft touch with character: the children behave like real children, with their bursts of moodiness, sibling rivalries, etc.
The main issue, really, is that I’ve read these books too much. Everything is all too familiar — though there are scenes that bring back the old dread and excitement even so, like Barney’s journey alone into the cave under the rocks, and Simon’s chase scene when he escapes with the map. This is the most juvenile of the books, and has worn the least well, all the same. It’s focused on the story from the point of view of the children, without a real idea of the seriousness and significance of the quest.