Thanks to Simon & Schuster for an advance copy of 'All the Summers in Between' in exchange for a candid review.

Wealthy Margot meets working-class Thea in the late 1960s as they work in a record store. Their opposites attract personalities, accelerating their fast-growing friendship until a tragedy occurs. They keep it secret and don't connect again until a decade later when Thea is married with a kid, and Margot needs help (again). It's highly readable, but a few plot developments didn't ring true.