It's a blog! Mainly of book reviews.
I read this probably not long after it was re-issued in 1989. I remember it as giving a deep insight into the pagan Celtic life and mind-set, relying heavily on the limited amount of Celtic literature that remains to us and within that most heavily on the Irish works as having been least Romanised/Christianised but also delving into historical and archaeological findings.
I have no idea how the scholarship stands up to current scrutiny.