There’s a liminal space just adjacent to grief. It’s where you live when anticipating loss that hasn’t yet arrived — the loved one with a terminal diagnosis, the crisis looming on the horizon. It’s the space you occupy when standing beside someone who grieves, trying to absorb a bit of their pain. Chronicling the intimate emotion of that space through a camera requires extraordinary sensitivity, the ability to observe without intruding and participate without invading. That’s what makes two new nonfiction films so remarkable: The Eternal Memory, directed by Maite Alberdi (The Mole Agent), and A Still Small Voice, from...