Over the past decade, the Brooklyn Public Library has hosted a late-night event that’s part-performance and part-pop-up third space. Night At The Library, which will run at BPL’s main branch at 10 Grand Army Plz from 7 p.m. Saturday night to 2 a.m. According to the event’s website, this year’s theme is “The Sky Above Brooklyn –The Philosophy of the Sublime,” through which organizers aim to demonstrate that “the reality we experience is only a small part of a much bigger picture.” Adwoa Adusei, manager of BPL’s Library for Arts and Culture, explains how the evening’s programs will speak to that theme.