You were exploring the whole sister location (FNaF 5) pizzeria, you've got to be careful.. but don't worry, there is a voice somewhere that can guide you, you light on the animatronics to see if they move or not, until you hear a faint, feminine voice.. it was beautiful and peaceful..

"Save me a dance for another day, perhaps.."

you realize it was Ballora, the main dancer at the pizzeria, along with her minireenas.