Despite Joni's best efforts, things aren't quite the same as usual and in an effort to shake things up, she suggests each friend write an anonymous letter revealing a deep secret or problem that can be discussed, and, hopefully resolved by the others. This exercise doesn't go quite as Joni hoped, but things only get more intense when Joni discovers a fifth letter, one that reveals a shocking secret that could shatter their little group. Although the letter writer had attempted to destroy the evidence, Joni cannot unsee what was written and thus the mystery of who wrote it and why begins.
There are many themes explored in this book - friendship, relationships, the difficulty of keeping all the balls in the air and The Fifth Letter addresses and satisfactorily resolves each element of the storyline. It is a book that will have you reminiscing about old friendships and celebrating moving on in equal measure.