A bronze group stood upon the landing, hidden from me by the corner of the wall, but its shadow fell with marvelous distinctness upon the white paneling, and gave me the impression of someone crouching to waylay me. I stood rigid for half a minute perhaps. Then, with my hand in the pocket that held my revolver, I advanced, only to discover a Ganymede and Eagle glistening in the moonlight. That incident for a time restored my nerve, and a porcelain Chinaman on a buhl table, whose head rocked silently as I passed him, scarcely startled me. (29)
We've already seen that the narrator is unnerved by the older people and the rustling he hears at the top of the stairs, but this is the first instance in which he’s genuinely scared. How do we know? He has to "recover his nerve." It starts to look as if our narrator might be more easily spooked than he originally reveals. And what scares him in this case? It’s the appearance of an everyday object as something threatening in the dark.