For as long as women have had friends, they've got us drunk, spilled our secrets, bailed on plans and meddled where we wished they wouldn't. They've also held back our hair, sat with us while we cried and made us feel altogether invincible.

Maybe none of us is perfect. Stirred by her own disappointments in friendship, cultural historian Tiffany Watt Smith sets out in pursuit of the rule-breaking women who offer a messier, more expansive vision of the connection we just might need the most.