Fin and Betty s close friendship survived Fin s ninth-grade move from their coastal Maine town to Manhattan. Calls, letters, and summer visits continued to bind them together, and in the fall of their senior year, they both applied to NYU, planning to reunite for good as roommates. Then Betty disappears. Her ex-boyfriend Calder admits to drowning her, but his confession is thrown out, and soon the entire town believes he was coerced and Betty has simply run away. Fin knows the truth, and she returns to Williston for one final summer, determined to get justice for her friend, even if it means putting her loved ones and herself at risk.