The night brings many things—crime, debauchery, romance, freedom—and directors have long been drawn to that after-hours loosening of inhibition. For 20 days this August, the Metrogaph is screening a series devoted to nocturnal voyages. Among the movies on the roster are Michael Mann’s Collateral, Gaspard Noe’s Irreversible, Richard Linklater’s Before Sunrise, Martin Scorsese’s After Hours, and Michelangelo Antonioni’s La Notte. The program delves deep into the complex activities that take place while most people are sleeping. —Jeanne Malle