At the age of 89, Julián takes one last bus ride to El Paso, Texas, to visit his daughters and their children - a lengthy trip he has made without fail every month for decades. After returning to rural Mexico, he quietly starts building a house in the empty lot next to his home. In the absence of his physical visits, can this new house bridge the distance between his loved ones? Over several years, director Iliana Sosa films her grandfather's work, gently sifting through Julián's previously unspoken memories brought up by the construction project and revealing both the daily pragmatism and poetry of his life. WHAT WE LEAVE BEHIND unfolds as a love letter to her grandfather, as well as an intimate and insightful exploration of Iliana's own relationship with him and his homeland.