Dramatic irony and time
This novel exploits the dramatic irony of time by removing the blinders from Sadie's eyes. Now that the crows have teleported her back in time, she is able to peer behind the veil to see the unfortunate and painful truth about her family patriarch, and in a much more nuanced way, of her own character. If she is essentially the same as her parents and forefathers, then she must also have a capacity for murder and evil. She also understands time better after a religious experience at a local ruin.
The irony of generations
There is a subtle ethical irony concerning generations. This is fairly common in world literature, including the Bible, famously. In the ancient Jewish scriptures, the prophets go back and forth about whether a person's evil behavior leads to ethical consequences in the lives of their descendants. That would be ironic, because technically, it had nothing to do with them. However, when Sadie loves her great-grandfather as much as she does, and then discovers his capacity for true evil, she realizes that she actually is ethically responsible, because she realizes that she has denied her own capacity for evil. Because it is her own grandfather, she realizes that she herself is liable to do wrong.
The crow irony
One of the most obvious ironies of the novel is the part where talking birds teleport Sadie back in time. More technically, the irony is not the crows; it is their magic. This irony boldly points to the inherent magic of the earth's nature. The land remembers the sins of the past even though Sadie doesn't know anything about that. The crows help and guide her while also providing a judgment against her family for their sins. In another ironic twist, Sadie takes this as a kind of moral encouragement. She respects the privilege of their insight.
The accidental sacrilege
Even in Sadie's own personal point of view, her forefather's behavior constitutes sacrilege. This is true because she respects the religious sacredness of a local ruin where ancient men placed stones in patterns around a pool of water. Without ever having discovered that, let alone respecting the meaning of it, Clarry destroys the valley by flood. He plays God by flooding the earth, and in the process, he covers up a murder and destroys a sacred ruin. Now, when Sadie goes back to her own present, those ruins will not be there for further contemplation.
Scandal and irony
Scandals are often scandalous because people who commit heinous crimes often are careful about getting caught, so that there is some confusion about whether anything happened, or what really did happen. A dramatic irony of precisely that kind provides the plot's drama in this dramatic novel. The scandal is increased in volume because the sin is murder, and because the sinner is Sadie's beloved patriarch, a man well-respected by the community.
