Quite a strange read. Interesting concepts and description of Mayan culture (I won't comment about whether it's exact or not, as I don't know enough about it as of yet), seen through both the prisms of archaeology and of visions of "shadows of the past". Interesting mother/daughter relationship, too, since Elizabeth and Diane have been estranged from years, and neither does know how to take the right steps to mend the gap.
In general, I liked how human relationships were portrayed in this novel. There is not totally right or totally wrong, and even the people who behave as assholes aren't shown as a surprise: other characters aren't stupid, they kind of expect the outcome they may (and will) get, and while it's somewhat bleak, at least the author dosn't come up with excuses (the characters' "excuses" are feeble and shown as such).
Interesting as well was the depiction of how society reacts to "strong women". Zuhuy-kak was a strong-willed priestess, and her enemies deemed her as mad. Elizabeth wanted to have a life of her own, something that clashed with her husband's expectations of her, and so she was deemed as unstable. Perhaps that theme felt stronger in the 1980s-early 1990s, when the book was first published, but I think it still hits home today—society has changed... but not so much.
On the other hand, I felt let down by the high stakes the blurb led me to expect: more danger, more drastic choices... that never really took place, or not in a dramatic enough fashion as to really make me feel that Elizabeth and/or Diane was threatened. I would've liked to see something closer to a resolution when it came to the mother-daughter relationship, too. The novel's too open-ended, leaving room for more, when part of that "more" should've been included in it.