Tarell Alvin McCraney’s Head of Passes was a majestic mess when it premiered at Steppenwolf Theatre in April. A gulf-coast update on the Book of Job, with an African-American widow named Shelah sitting in for the Old Testament schlimazel, the show fell in on itself just like Shelah’s house does when a torrential rain knocks it off its foundation. Still, there were survivors—chief among them Alana Arenas, who played Shelah’s profoundly troubled daughter, Cookie. Arenas has acted the part of a lost soul for McCraney before: as an ethereal young athlete run aground by ghetto values, she was astonishing in his In the Red and Brown Water. Arenas’s Cookie was something else entirely. Carrying a secret trauma, the character is industriously irresponsible, compulsively self-destructive, as shattered as any veteran with PTSD. Arenas gave us every shard.