The opening passage is unforgettable. An unstable passenger has hijacked the bus and started killing hostages. But it occurs so fast, so unmelodramatically and without foreshadowing, that you barely have time to react. You are stunned. Yet, Aoyama later proves himself extremely adept at foreshadowing, although, again, in an unmelodramatic way.
Subsequent narrative occurs in an environment in which a serial killer is stalking women.
The three form a very tentative, fragile familial bond, with the children's young-adult cousin. Yet their environment is a dangerous place where memories stalk these characters like ghosts. But not yet a doomed one.