Paul Erdős owned almost nothing, kept no permanent address, and spent his life traveling between mathematicians' homes with a suitcase, working on proofs at their kitchen tables and moving on. George Csicsery's film follows him in his eighties, still fueled by coffee and amphetamines, still handing out cash prizes for solved problems, still calling children "epsilons" in his private vocabulary. Colleagues including Ronald Graham, who managed Erdős's finances and stored his mathematical archive, describe a man who treated collaboration itself as the point of the work, publishing with more co-authors than anyone in history and giving rise to the "Erdős number" as a running joke about mathematical kinship. The film shows him lecturing, arguing over conjectures in number theory and combinatorics, and reciting his own idiosyncratic sayings about God's imaginary book of perfect proofs. Interviews with fellow mathematicians fill in the biography: childhood in Budapest, decades of statelessness during the Cold War, and a life organized entirely around one pursuit. It is a portrait of a man who measured wealth in theorems.