Noah and Helen begin divorce proceedings that prove complicated; Helen sparks up a surprising relationship with someone new; the Solloways' children each struggle with the divorce.
Alison's summer with Noah is interrupted by a visit from Cole; whose self-destructive lifestyle is raising concerns; Alison stumbles upon a job opportunity.
Alison's relationship with her hosts takes a sharp turn; Alison is furious with the contents of Noah's book; tensions arise between Cole and Scotty as he crosses paths with Luisa once again.
Alison's mother raises concerns about her and Noah's new lifestyle. Alison confronts Noah about his book. Meanwhile, Cole lashes out at Luisa and is further alienated from his family in the wake of startling revelations.
On the college campus where they first met, Helen is amazed to see Noah in a new role, and bewildered by Whitney's future plans. Meanwhile, Noah is in danger of spinning out of control as his fame and related temptations escalate.
Alison weathers a momentous journey alone. Helen receives unexpected attention from a sexy yet exasperating source. Noah faces a terrible reckoning. An array of challenges pushes Cole to the very edge.
Noah grapples with essential questions. Alison begins to doubt a recent ambition - and renewed interactions with the Lockhart brothers force her to consider a harrowing possibility.
Cole and Luisa take a serious step forward. Meanwhile, a series of revelations cause Noah to reconsider everything he thought he knew about Alison - and a momentous decision Alison makes may just end their relationship.
Events set in motion long ago come to their conclusion. Alison is honest with Noah -- and herself. A dispute between Cole and Scotty is followed by tragedy. Meanwhile, a turn in Noah's trial results in a shocking event.