Rat Pack cunningly disguises its humble means with a prodigious nervous energy. Twitching back and forth through time, we spy on the rise and fall and rise and maybe fall again of Joe and Nicole and Teo and Marissa, two interlocking couples on the outskirts of Millennial Brooklyn. Behind the restless flow of scenes (complete with titles marking off the remaining minutes) is a growing undertow of grief, painting a decidedly un-rosy portrait of youth.