Lucas Hnath, recently represented on Broadway by the spun-from-fact Hillary and Clinton, and soon to be represented at the Vineyard by Dana H., a story drawn from family experience, is cleansing his theatrical palate between them with The Thin Place, a story of the afterlife that conjures up the eerie worlds of Conor McPherson and M.R. James. The dedication to Ricky Jay, the late magician, indicates Hnath is out to perform his own sleight of hand with a deeply unsettling ghost story.