The correct answer is on the bust of Pallas.
In Poe's famous poem, "The Raven," the protagonist is alone in his room when he hears a knock. It turns out to be a bird, a raven who was knocking on the window to be let it. Once he is, he perches itself on the bust of Pallas, which is quite symbolic in itself. Pallas is goddess of wisdom, according to Greek mythology, so when the raven sat on her sculpture, it started saying 'wise things' to the protagonist.
The protagonist is wondering whether he will ever see his loved one again and whether he will manage to get over her (given that she died), but the raven's only word is Nevermore.