What does it mean to live without the person you loved most? In The Sum of Grief, board-certified chaplain Jessica Shannon explores the quiet arithmetic of loss: the calculations we make, often without realizing it, when we measure our days against the absence of someone who shaped them. Shannon was seventeen when her mother died. In the decades since, she has spent her career sitting beside the dying and the grieving, first as a hospital chaplain and later in hospice care, learning what the textbooks leave out about how loss actually works. This memoir moves between those two vantage points: the daughter who lost her mother, and the chaplain who has since walked that same road alongside hundreds of strangers. What emerges is a framework that validates what so many feel but rarely hear spoken aloud. Grief isn't a problem to solve. It isn't a stage to complete or a wound to close. It's the proof of how deeply we loved, and it deserves to be treated as such. Written with the clarity of Joan Didion and the emotional precision of Sloane Crosley, The Sum of Grief is for anyone doing the quiet math of loss and wondering if the numbers will ever add up to something bearable. They won't, not in the way we expect. But Shannon shows how they can add up to something else: a life that holds both the absence and the love that caused it.