“I kept thinking how [we] had a really unhealthy family,” writes Elizabeth Strout in her 2016 novel, My Name is Lucy Barton, “but I saw then too how our roots were twisted so tenaciously around one another’s hearts.” The Son, the final installment in a tenaciously twisting family trilogy by Tony Award-winner Florian Zeller (The Mother came first in 2010, then The Father in 2012), is about a teenager named Nicholas, who is suffering the twin effects of divorce and creeping depression. The result is a spot-on, emotional production from a talent the Times of London has called “the most exciting playwright of our time.” —J.V.