Who is the narrator, can she or he read minds, and, more importantly, can we trust her or him?
Third-Person Omniscient
Although the novel's narrator sure does like to get his free indirect speech on—that's speech that taps into the thoughts and feelings of the novel's fictional characters—it's clear that the narrative voice is not at all limited by those characters' points of view. There are multiple moments throughout The Hours when the narrator communicates information that none of the novel's characters could possibly know, as in this passage from the novel's Prologue:
Here they are, on a day early in the Second World War: the boy and his mother on the bridge, the stick floating over the water's surface, and Virginia's body on the river's bottom, as if she is dreaming of the surface, the stick, the boy and his mother, the sky and the rooks. An olive-drab truck rolls across the bridge, loaded with soldiers in uniform, who wave to the boy who has just thrown the stick. He waves back. […] All this enters the bridge, resounds through its wood and stone, and enters Virginia's body. Her face, pressed sideways to the piling, absorbs it all […]. (Prologue.7).
This is an omniscient narrator at work: one who can go anywhere and see anything—and who knows all that can possibly be known about the universe of the narrative.