An aging Brooklyn artist, his young assistant, and a blind friend arrive by rusted retro car; a Puerto Rican woman and her teenage grandson arrive on foot with a rattling grocery cart; and a hyperactive twenty-something and his stoned companion leave a Bushwick loft to navigate via subway. In “Spoils,” three New Yorkers embark on an intimate journey through the culture of dumpster diving, illuminating a practice as old as agriculture.