Weakness follows the life of high school teacher Joshua Polansky (Bobby Cannavale), whose world is crumbling around him: his wife, Elizabeth (June Diane Raphael), wants to start swinging; his mother, Lenore (Phyllis Somerville), thinks she has terminal cancer; and his autistic brother, Pete (Keith Nobbs), who resides at an assisted living home, only connects outside of himself through baseball, games or an occasional burst of anger. At school, things get complicated as a love triangle of sorts develops between Joshua and his teaching colleagues, the wise-cracking Bart (Josh Charles), and idealist Katharine (Lily Rabe), who only has eyes for the married Joshua. When Elizabeth leaves him, Joshua retreats from his adult life and responsibilities and begins dating Danielle, (Danielle Panabaker), a former student who has postponed attending college. Joshua s subsequent regression and indecision fail to mask his anger and hurt, leading to a series of events that force him to reconsider not only his decisions, but the subtle and profound ways that people affect one another.
