From Goodreads. For Alice, life's a bit too boringly grown-up lately—weekends at weddings and baby showers; celebrating friends' transitions to a life she isn't quite up for yet; and a sweet, stable boyfriend she suspects she's outgrown. So when she meets Gretchen for the first time, it feels a bit like falling in love. Gretchen, with her air of impulsiveness and intuitive style, is that rarest of treasures: a true friend who knows how to have fun. Plus there's Gretchen's gorgeous brother, Bailey, who might turn out to be exactly what Alice needs. Before she knows what's hit her, Alice's brilliant new best friend is turning her world upside down—seemingly for the better.
But Gretchen has a dark secret, which, like a time bomb, won't stay hidden forever. The explosion may teach them both more than they ever wanted to know about how female friendships can go frighteningly wrong.