Peter agrees to hold a prom; Shelby grieves when Scott leaves Horizon; Ezra is tempted to take drugs; Sophie asks Peter to marry her.
Everyone braces for Parents' Weekend; Scott won't speak to Shelby when she returns to Horizon; Peter asks Sophie to marry him.
Peter's growing drug addiction leads to a breakdown; Scott tries to forge a new bond with his estranged mother.
Peter is injured while training for a mountain climb and begins taking painkillers; Shelby takes care of her abusive stepfather.
Shelby and Scott rehearse Ezra's play, which resembles "Romeo and Juliet"; Sophie battles intense pain; Peter's brother pays a surprise visit.
Daisy must return home for her mother's funeral and face the alcoholic father she tried to kill; Juliette and Auggie grow closer.
Shelby gets lost in a snowstorm during a wilderness hike after Scott pressures her to talk about her past; Peter's father has a heart attack.
When the kids discover an undercover reporter in their midst, they concoct wild stories for her; Daisy realizes that Shelby's tale of abuse and prostitution is true.
Peter and Sophie are irritated when Chloe, Horizon's new CEO, brings in a director to make a promotional film using actors.
A new student quickly antagonizes his schoolmates, while his father is forced to trek through bear country with Peter.
After Juliette and Auggie run away, Auggie is arrested for shoplifting food, and Peter must plead his case at a probation hearing.
Ezra despairs when he learns that his parents' happiness is a charade; Juliette cuts herself when she discovers that she isn't invited to her mother's wedding.
Scott flees an encounter with his abusive stepmother, stealing down river in a kayak; Shelby falls in love with an abandoned horse.
After a new student commits suicide, Frank takes everyone to Hope Falls, where his own son overdosed 22 years ago.
The students seek refuge in the main lodge as a violent rainstorm rocks the school, while Shelby takes advantage of the turmoil to seduce Scott.
Peter deliberately interferes with Scott's plans to run away, taking him instead on a hang-gliding expedition off of Devil's Peak.
When Katherine is caught in a compromising position with Hank, she jeopardizes her impending graduation from Horizon.
Juliette falls into an uncharted cave and discovers the skeletal remains of an American Indian girl; Peter organizes a search party.
The teens at Horizon must learn about teamwork when they enter a torturous dawn-to-dusk triathlon. With Joe Lando.
Peter goes to New York to secure financial help from his father to save the school; the students are apprehensive about taking the PSATs.
When Peter's students are recruited to search the woods for a missing girl, Auggie is appalled by Shelby's apparent lack of concern for the child.
A former Wall Street highflier spends three years as administrator at a progressive school in the Northwest.