Eboni Booth’s Primary Trust is a tender and riveting play about trauma and the difficulties of human connection that is by turns funny and upsetting, and ultimately uplifting. Its power lies in Booth’s ability to avoid cynicism and create characters capable of genuine surprise, without veering into melodrama or oversentimentality. Director Knud Adams, who also directed Booth’s Paris at the Atlantic Theater in 2020, achieves a smart balance between naturalism and the unreality of a memory play, with a superb cast, led by William Jackson Harper in a performance of uncanny vulnerability.