Blair breaks up with Chuck because he sold her and that makes her feel completely worthless and unappreciated. Chuck is a "monster"
Chuck gives her a few days, not realizing the damage he's done to her
He realizes it once he finds out she's moving to Paris to "start anew" and find someone real
He begs her to come back but she doesn't
He spends the whole summer drinking until he finally decides to go find her..
At Paris, they see each other. Stuff goes down. He manages to convince her to return to NYC
Fall begins, Blair finds out Columbia accepts her (secretly thanks to Chuck)
She finds out, they become friends again
And here's where I blank out...
Blair dates around. Chuck is pretty miserable without Blair but remains a good friend to her - in truth, Blair does this because she just wants to show Chuck that someone can treat her right (so sort of denial of truth) but she soon realizes Chuck is the best person for her. But she doesn't want to get with him because he still hasn't apologized for what he did to her. She refuses until he apologizes for his mistake because she wants him to realize his mistakes.
Blair starts getting "serious" with a guy. Chuck loses it
Blair goes to talk to Chuck. Explains the situation.
Chuck apologizes for everything & sees the ring
And here's where I blank out again...interruption: problems they had in their relationship part I = lack of trust, lack of appreciation, scheming towards each other, feeling safe. Okay by the time they get together, this should be resolved