What happens when the imagined life and the stories we tell ourselves become terrifying, given our human ability to inhabit both mental and physical worlds? Bertram’s third full-length collection pivots on an extended piece of creative nonfiction, “Forecast,” which shows how obsessive thinking can begin in actual occurrences that are then exploded in the imagination. The science is personal, as the factual is tinted and stylized, filtered through a self grappling with the difficulty of knowing what is “real.”