Love Letter Lost: A Second Chance Romance - Hillary Slaughter

After he broke her heart, Mallory Roberts thought she'd heard the last of Ridge Matthews. Now, forced to work together to save their friend's wedding, will these former high school friends part as friends, enemies, or something more?
After a chaotic school year, all fifth-grade teacher Mallory Roberts wants this summer is to renovate her fixer-upper apartment bringing her one step closer to financial independence, and proving to her family once and for all that she is no longer that little love struck teen. But first, she must survive being a bridesmaid for her cousin, Livvy. As Mallory helps pack up Livvy's belongings, she discovers a sealed letter addressed to herself tucked in Livvy's yearbook. Mallory opens it, only to discover the letter is from Ridge Matthews, her lifelong friend and possible true love who ghosted her after senior prom. Surprised by the letter, Mallory confronts Livvy who confesses to hiding the letter several years after Ridge ran away to protect Mallory from additional heartbreak.
When Livvy's wedding reception falls apart, Mallory agrees to step in to save the day, because it's what family does. Not to mention, it might finally prove to her family that she can stand on her own two feet. Unfortunately, in a misguided attempt to make amends Livvy's recruited help: Ridge.
Mallory wants to keep him as far away from her-and her heart-as possible. But with the wedding fast approaching, Mallory and Ridge are forced to set the past aside and work together to save Livvy's big day.