Seventeen-year-old Iris Vale never planned to spend her summer trapped in the quiet town of Bellmore after her parents' divorce. Lonely and desperate to escape, she discovers a hidden mailbox in her grandmother's attic containing a mysterious letter from 1986 written by a boy named Elijah Mercer. What begins as an impossible exchange of letters soon becomes something far deeper. Across decades, Iris and Eli share their fears, dreams, heartbreaks, and hopes through a magical mailbox that somehow defies time itself. But when Iris discovers Eli vanished shortly after the letters were written, their connection becomes dangerous. Every attempt to change the past fractures the present, and Bellmore's strange phenomenon known as "The Echo" begins tearing reality apart. As timelines collide and memories shift, Iris must choose between protecting the future or saving the boy she loves. Letter from the Past is a sweeping young adult romance filled with mystery, magical realism, heartbreak, and a story about the people who change us forever, even across impossible distances in time.