Told in dual timelines, one set in 1967 and 1977, this book follows Thea, a working-class woman in the Hamptons at ages 20 and 30, and how she defines herself through her relationships with others, specifically her best friend, Margo. Margo is wealthy and fun, but flighty and not trustworthy. The two grow close in the summer of '67 working at a record shop together, but lose touch after a surprisingly dark end to the summer. In '77, Thea is married and has a daughter, and until Margo comes crashing back into her life, they haven't talked in 10 years. 

This was slow-paced, and mostly just focused on building the relationship between Margo and Thea. The twist reason they lost touch was predictable, but the resolution to the present-day timeline was well done and bookended the story well with parallels to the past. However, Thea was a doormat, and Margo was a narcissist. I often enjoy reading stories about bad people, but I didn't get the feeling that I was supposed to dislike Thea, who narrated the story. Her life was depressing, though, and I wanted to shake her when she let people dictate her decisions.

My favorite part of historical fiction is the world-building that helps immerse me in the time period, and some of that was spot-on here, but other things took me out of the story. For example, a scene when the two women are on a sailboat and pull out "Colt 45 beers". Colt 45 is a malt liquor, not a beer, and it's not something I could easily picture two society women in the 70s sipping on their boat. There are a lot of interesting relationship dynamics here, and I think the right person might really enjoy this, especially as a beach or pool read this summer, but it wasn't a memorable read for me. Thanks to NetGalley, the author, and the publisher for the advance copy in exchange for my honest review.